You probably won't get EXACTLY the perfect shock for less than $100, but what I'd suggest is taking the measurements of the stocker and finding a similar one for a HEAVIER vehicle. Most of the auto parts stores have buyer's guide info that breaks shocks down into types (upper stud, lower grommett,etc), then give extended and compressed lengths, dia, etc.
I,ve found lots of shocks this way when repl.were not available. Also had a HOT Opel Rallye (don't laugh, it was), that I ended up using Corvette shocks on for racing and drags. A friendly parts man can be your best help. Good luck