5th Gen (desireables, anyway)
avoid breeze models like the plague
Si and VTi are the same thing except Si has the last development of the ZC engine and the VTi has the first generation SOHC VTEC engine - they make identical power at 96kW and I think the VTi had 1nM more torque. They both come with all the fruit: power everything, tacho, disc brakes etc. Average prices $9,000-$12,000, up to $14,000 for a good one. Made model years 92-95.
6th Gen
CXi = base model. Already commented on.
GLi = better equipped, all wheel discs, CD, tacho etc. Skip if you can get VTi-R
VTi-R = first potent model with B16A in Australia (STFU Pete

). BUY THIS CAR IF YOU CAN STRETCH TO $16,000-$17,000!!!
Anything else you want to know?
My preference would be pick up an Si with high kilometres and drop an EG spec SiR B16A into it for bolt in 160hp.

Oz