Ok, springs, Deavers are going to be your best bet, they've been in the game quite a while and make a Jeepspeed specific application. If you don't want to run Deavers, some guys run the 8" skyjacker coils and cut them down to the height they want. Leaves, again, if not Deaver then look into National or Alcan. They both make excellent springs, but you're gonna end up spending more to get something custom built through them most likely.
As for arms, any good name brand arm should do you fine, I'd stay away from Rusty's stuff, but as for everybody else you should be fine. Go with heims or uniball style arms, not bushings. Heims/Uniballs will allow the axle to flex better and droop the way it's supposed to without bind. Drop brackets, any will work really, I'm running rough country, as Jason is a supporter of this site and makes a kick ass deal on RC stuff.
Shocks are really up to you. If you want to stick to stock mounting locations you can run a 2.5" resi up front and a 2.0" in the rear. If you want to build a shock hoop through the floor like a lot of guys do, then you're pretty much open to any size you want to run. Fox, Bilstein, Swayaway, King, etc. are all good shock companies.
As for height, the lower the better really. Mine is right around 5.5-6" and it's too high for me. I'd like to lose about an inch
