whats best type to go? healer?
whats best gear to get
best stats..etc etc..

Best mage = healer and damager dealer.
For gear, you'll want to get as high INT on both weapon and armor.
For charm, get as high EE as possible, and for healer charm, get as high EE as you can as well.\

Mages only wear robes, so when you Cata you'll want to stay in the back.
Try to get a heal charm for 20+ because that is when people will start to need heals.

You usually use ee charms, int weapon and int armor.
And you normally stat fully int

so everything into intelligence?

Correct.
If you want to heal more, you'll want Heal Mastery % as an extra mod on items, but INT is the primary stat you want.

I would strongly suggest putting 5 of the first 10 points into Vita, simply to help give him more HP throughout the climb. Some even go 10 Vita, the last thing you want is your main source of heals dying on you.

The rest is correct. EE charms/heals, Int/Heal Mastery gear, and stat Int.

thx
taking any more info if anyone above missed it

If your friend plans to cata and doesn't have lots of Fg, I would say full healer.
Stat all intel (5-10 vita first)
Buy healmastery items
healcharm

If your HC, I would reroll and go with a tank.