KA

Pros:
Displacement
Better designed head
400whp on stock rods, crank
Offer nistune, safc, cheaper motor, lots of torque.
Cons:
Shitty stock head gasket
shitty pistons
shitty intake manifold
not factory turbo'd


SR20det-
Pros:
Factory Turbo
Decent Power
Cheap tuning Safc, or nistune,power fc etc
Cost around same as KA-T
Make 350 whp with minor mods (turbo,hg,headstuds,rockers,tuning etc)

Cons:
Shitty head design (rockers shoot out)
VERY abused usually
Shitty Headgasket
Shitty design oil pan (minor dent and its a wrap)
Parts can be harder to get ahold of

These are off the top of my head, and from experience.