It's basically a baby GT-R man. The downside is that it won't fang like a GT-R in stock form but with a bit of fettling, it'll get up and boogie with excellent results.
The upside is that when a RB26DETT goes bang, you'll be looking at big bucks to fix it. When an RB20DET goes bang, you won't be sitting in your bedroom with your head in your hand balling your eyes out.
If you want to later on down the track, you can drop a 26 in if you have the know how, but you'd be happy with a mildly worked 20.
As far as the price is concerned, if you have half a brain cell, all those items can be fixed with minor ease and the parts should be easy to get hold of. I have seen the Gts-4 with GT-R headlights as well as Gts-t type, so it may be either. The GT-R headlights are a projection style (little round light with a squarish light next to it).
HICAS is a pain in the butt. Many of us disconnect it with a lockout bar, but if you really want it working do a search as there are a few factors that come into play when they go. It could be a fuse as mentioned previously or it could be the reservoir in the boot is low in fluid.
Front bar, go aftermarket.
Though it's your call what you do, if it was me, I'd grab it. Minor issues only.