Two of my mates have moved on from turbo starlets to MR2 turbos. Both pretty stock rev 3s. They are nice cars but really depends on the setup. If it is 1.9 bar then youve had it mate, but surely its gotta be forged and running a different turbo to push that boost ? The standard turbos in MR2s couldnt handle that pressure.
Or buy it, build a wee bit, leave it, do a bit more, leave it, leave it some more, work on it, eventually finish it, drive it, blow it up, scrap it. Then get another and start again haha.
And whilst your at it tighten stuff like hub nuts, bottom arm bolts, drop links etc. These can all cause knocking noises which can be difficult to trace.