Yes it is very possible a few have been done already. Go to
www.afterdark-tuning.com they are in Iowa and do the swap pretty cheap compared to others. The RB25DET is your best bet it is the engine out of the GTS-T skyline it is already rear wheel drive. You have to use the skyline crossmember but other than that it is pretty straight forward. The wiring is a pain but well worth the trouble. The RB25DET's tranny will bolt to the RB26DETT to convert it to rear wheel drive if you have to have the 26. The RB26DETT is a lot more money and a lot harder to install(lots of custom work). If I can help any more let me know.