...and I would think for that kind of money I could get more horsepower and cheaper replacement parts going with something else...
You can get a bit more our of a 1.3 with headers, exhaust and carb mods. Gearing can help the driveability, too.
But nothing beats a bigger engine!
After going through the "add a header, bigger exhaust" phase, I finally broke down and bought a remanufactured 1.6 8-valve. It turned out that I was able to keep the previous mods with the bigger engine, but the most impressive performance change was the new engine. It cost more, but I saved a lot (and learned a lot) installing it myself.
If you can do-it-yourself and can find a decent engine at the wrecking yard you can save some money AND learn a lot. Although there are a number of bigger engines that have been installed in a Samurai, the clear favorite is the 1.6 16-valve (lots of aftermarket install kits and FUEL INJECTION! Great on the trail!) followed by the 1.6 8-valve.
Check out the vendors on the homepage of this site for more info on swap kits.
check out
http://members.cox.net/aftermarket4x4/ for information on swapping the 2.0L engine.