I am currently doing exactly that. I have a 96 GX hatch and bought the running gear from a smashed 98 WRX. If you are doing the work yourself its worth it if not then dont bother to put it nicely. Seeing as you have a 95 model you would be best to buy the same model front cut to suit it or you will have problems with mating the dash to the wiring harness etc. So far i have done the rear end conversion which involed removing the rear axle assembly and fuel tank and replacing them both with the AWD items. That was a days work in itself. If you do go ahead be prepared for little hiccups along the way, such as the AWD fuel tank straps are different to the FWD. I am doing the work on my car myself so to me i think its worth it, but as an estimate here goes,

Front cut with wiring loom and rear diff and fuel tank etc - $3500 - $4000 unless you want sti then its gonna be near double that.
Additional items you will need along the way - $1000
and at a guess i would say for the labour you would be looking at around $1500 - $2000

So in saying that budget around $7000 to get a shop to do it.
If you sold your car and put $7000 towards it would you be ahead?