I think for the cost, you should look at a Chevy v6 or v8'for the following reasons
Cost- rebuilding an Inline 4 may cost you the same as a v6. The 91 was I think the 1st year of fuel injection, and you may have to replace that, the computer, block as well. If its legal here in Va, I'd check it out
Time, I helped the guy who did my swap out in 02. Took about a week to do it, & it took awhile to lose bugs
Scope, all things being equal, time & cost, might as well pick up a few extra horses.
Again just a suggestion