Welcome to NICO. Nice to see another person from Saskatchewan on forums! Vonda is so ridiculously small haha, but I lived in Clavet so I'm not one to talk. SR20 in a 720 hey, were you thinking the DET or just a DE? I would think both are very possible, given a KA24 swap is done frequently into these trucks, which have the identical motor mounts of a SR20DET. If you had only planned on the DE, have you considered a KA? Easier to find (not like anything is easy to find around here)
To be honest however, I do not know from personal experience if it is doable and if it is a lot of work, as I have left my 720 with the stock Z24.
Btw, it's a little unrelated but, if you are looking for parts, Ron's 4x4 salvage has a fair chunk of 720's. (It's just before Borden) Just don't expect to find any good body panels, I pretty much took the last good set they had lol. Taillights are a no go either. (I still don't have new ones, had to use Tuck Tape >_>)