I currently have just a 2" BB shackles on my xj, and am planning to add a 3" or 3.5" full leaf pack kit, and leave my 2" BB on.
The shocks question is will i need 5" shocks because of the total lift?

Lift question - What is a good 3" kit for the money? I'm looking at rustys, RE, RC and even rancho right now.

SYE - will i need a SYE/CV driveshaft with this setup? i know you need one on bigger lifts but im not sure how the BB affects it.

 

yes you will need bigger shocks and you will also need an sye or you will have vibes as for the lift brand RE is probably the best out of the ones you listed but you will pay a little extra for it RC is also a good choice that is what i run mine your also gonna need longer brakelines and lower control arms

 

with a 3" kit itll come with 3" shocks, so would it be possible to contact RE or RC and make a deal to include 5" shocks?

 

RE kits do not come with shocks in fact no all kits come with shocks. If they do come with shocks just call em up and ask for longer ones most companies will accommodate.

 

so 5" shocks would be good?

also can i run 31" tires without regearing?