I live in Norway and getting a good quality reverse hyper and similar equipments seem to be hard or costly. I've been to plenty of gyms over the country and I've never even seen one.

The cheapest alternative I could find was from this website, which seems to have a high quality for the price:

https://www.strengthshop.co.uk/reverse-hyper.html

I am also ordering some other stuff to have at home (like a simple GHR device) and stuff to bring to the gym, like resistance bands and a dip belt.

Also, I've not incorporated use of such equipment in the past, except for a dip belt for static holds or weighted dips/pull ups (just doing regular free weights), so I am not very knowledgable about the use of such.

Now what I'd like to ask you good folks is:

1. If you have input on that particular reverse hyper machine, do you think that one is a good choice?
2. I can't for the life of me tell for sure what plates to use (I'm not really experienced with what different dimensions are used). Do I order standard bumper plates from that site with 51mm holes? Will those work with a standard EU olympic bar if I get more space for a home gym later?
3. How much weight should I get in plates for the reverse hypers? I weigh about 88kg ~20%bf now, goal is 150kg squat and 200kg DL, currently at about 75% of those numbers (have been closer to that in the past, but been struggling with back problems)?
4. Lastly, what other gear would you recommend with powerlifting in mind, or deem unnescessary from my list below (not at a high level mind, just the goals I've set above; and staying injury free)?
4.5 Pertaining to 4) What grippers should I get for grip training, and to what level? Considering captain of crush, and currently my grip needs training bad. I've never done DL with straps and don't want to.

What I've added to the shopping cart so far:

-fractural plates; 8x0.25kg (my gym has 1.25kg plates and above)
-reverse hyperextension for home use - https://www.strengthshop.co.uk/reverse-hyper.html
-GHR for home use - https://www.strengthshop.co.uk/glute-ham-developer-compact-model.html
-resistance band 12 inch #1
-resistance band 12 inch #2
-hip resistance band 14 inch - https://www.strengthshop.co.uk/hip-band-camo.html
-resistance band 20 inch #1
-resistance band 41 inch #1
-magnesium chalk - https://www.strengthshop.co.uk/magnesium-carbonate-chalk-case-of-8-blocks.html
-resistance band for fingers - https://www.strengthshop.co.uk/expand-your-hand-bands.html
-grippers, captain of crush? which ones?
-dip belt
-ab roller (is this a good equipment to have? it's cheap at least)
-massage balls, I've got a foam roller allready-
-dip belt - expensive! but from reviews seems like it's top quality and I need one that can hold a lot of weight and distribute it in a good manner - https://www.strengthshop.co.uk/ironmind-de-rigueur-dipping-belt.html
-regular belt - I'm unsure if I should get one and starting to use it. On one hand I want my core to be strong, on another I want to stay injury free. And lastly I'm not even sure if lifting heavy without a belt helps for devoloping core strength. I'm guessing I should get one when weights get heavier, especially since I struggly with lower back problems (the medical term is something like degenerative changes and almost prolapse in two joints L5/S1 something).
this belt is on sale at half price, so might as well get it? https://www.strengthshop.co.uk/strengthshop-13mm-lever-belt-blue-ipf-approved.html

Last notes: and that's what I've got planned for this order. the resistance bands are meant for warmups and mobility, and later on I would like to add them to exercises. I can always order stronger resistance bands later as needed (light weight for shipping).
total price of the above is 1080£, 1300£ with shipping, plus 25% in Norwegian taxes unless I'm lucky I guess, bumpers and grippers not included in this.

I am ready to place the order, just want to make sure I get what I need.

Just do reverse hypers on the GHD. Or set a regular bench to an incline position and do them there. These are the two ways we do at our OL/PL gym
Attach a band for added resistance.

For powerlifting;
Adjustable rack, stable bench and a decent bar. If home gym go for bumpers to save the floor.

Would not go with the ab roller, sure you can find super cheap ones but still not necessary.

Lycka till lillebror mvh pappa Sverige.

@PlaaD
Thanks, I'll do a bit more research into that, but my gym(s) does not even have a GHD. They are pretty common in the north of Norway, but I've not been there with work for a couple of years.
If I were to do them in a GHD I would need a different model for that, than the one I've planned, but I think I'd prefer a dedicated machine for reverse hypers at home. I've seen youtube vids of coaches doing them on stability balls on the ground or on a bench, or just straight on a flat bench or incline. I'll try them on an incline bench and see how it feels, but I've got no bands as of yet (will be a first).

I don't have room for a rack, so not gonna get a bar or rack until I do have the space to build a gym. The bumpers would be for the reverse hypers, and then put on an oly bar when hopefully I get the room (and floor) to install a good rack (I'm tempted to tear down the old garage and build a home gym with "trev" above it haha).

Thanks for your input, much valued!

Obviously it's important to target the posterior chain and all, but investing in a reverse hyperexension machine seems a little overboard for most home gym settings.. maybe that's just me.

Agree.

Is there a particular reason why you must have a reverse hyper? I mean I've barely seen anyone in powerlifting or weightlifting who use it besides maybe Westside.