So I am following an aggro deck of sorts. It recommends using Death's bite but I do not have it.

What are two good subsitutes for it that would make the deck pan out?

http://www.icy-veins.com/hearthstone/warrior-aggro-rush-naxx-deck

face warrior doesn't really have a refined list.. in the version I was running I found deathsbite wasn't a good fit since you often are trying to maintain a board of low hp minions.
I found cursed blade was quite nice, for early game trades//and or just 6 dmg to the face..
captain greenskin
copy of charge for the bloodsail raider is nice
sir finley
task master isn't the best agro option
1 owl should be fine
another upgrade too.. I always run 2 upgrades + greenskin.
You have a lot of options here... again I don't think anyone can give you a 'best' agro warrior list.. the deck can get some wins.. but by no means top tier.