ive had a few 240s in my life as well.. if it was up to me only cuz ive been in this situation. i would slow down. investing in automobiles is risky business. IMO i wouldnt get a modified car, especially if its turbo'd like that sr20 unless it was installed by a reputable company, i just dont trust anyone enough to do it.
In my experiences, u gotta really wanna do this and be 100% committed. with that being said. i dont know ur financial background but restoring any car in general can get pretty expensive. cuz thats all ur really doing, is restoring the 240 to get it back to atleast mediocre driving conditions. if u really want that z just wait for it, and get urself a newer car to get u places for the time being. i guarantee u wont regret it, and i know ur wallet wont either