Wait what? Youre seriously reccomending the SR for Frontier Truck? Maybe you dont know enough about the KA.
I would seriously put the KA into the truck. The turck in Crew Cab and Extended cab weigh 1000 lbs more. Having an SR20 which produces less torque would be kind of crazy.
Browse over to KA-T.org or the KA24DE forum thread here.
The KA can make 300WHP very easily and even on an FMIC, Custom DP,Custom Exhaust, SAFC2(or Neo), Z32 MAF, some injectors, a cheap manifold and a SR T28.
Honestly, everything could probably be done for $2500 or less. An SR20 from a reputable dealer shipped and FMIC could come to 2500.
EDIT: Ha, Hell put in the VG33ER and upgrade the pulley and get an SAFC2 and some bigger injectors.

Torque monster and its boosted.