Awe come on don't give up so easily. V8's have been put into celicas before, it just ain't easy. Why not look at a little 3.5 Rover V8 or some of the smaller Toyota V8's.
If it is just plenty of power that your are after there are heaps of options in the toyota stables that will satisfy your power craving.
My 2L 6 cyl puts out about 150rwkw. Thats as much as most V8's will do and it's practically standard.