From what I've been reading, there is a good possibility that a 1mzfe can fit into the celica.
You can get a 1mzfe from a 97+ camry, solara, or avalon for about $1200 and it will probably have less than 50k-60k miles on it. The 1mzfe has been put into a few mr2s and from what I've read, they only place where the 1mzfe is bigger than the 5sfe is front to back. But I think that we may not have this problem since we probably have more room front to back than the mr2 does. It seems to me that this would be an alternative to a 3s-gte that would be about the same amount of work.
heres a few links
http://celica.net/cgi-bin/ultimatebb.cgi?u...t=002431#000019http://www.board.mr2faq.com/showthread.php...3449&perpage=15