You need but search and find many engines that have been fitted to a RA23. Personally, I won't spoil the breed by fitting a non-Toyota motor to one.
Try a 1JZ-GTE, or a 18RG, which gives you a range from one of the harder conversions, to the easiest. Look at a 1G-GTE or 1G-GZE as well. Uber web pages have been written on these conversions.
Mitch.