This is a very tough decision.
From what you specified as the S14 being super clean, IDK what to pick. My original car choice from the beginning was a 240sx SE. I ended up with a 200sx SE-R. But I have fallen deeply in love with my car and this world of FWD autos.
So for me, I just don't know. I love putting my pride and efforts into a car, that means alot to me. So to just hand it off is tough. Yet you are handing it off for a seemingly mint S14 with a suspension package and to someone who takes care of cars.
So, taking these into consideration, how fast do you want to go? I think for lesser money, you can make the S14 a beast and like, BlueRB stated, LOTS AND LOTS of parts out there.
Do the trade!