I have the last year of the old body style, 98 2 door Tracker. All comments reference the old body.
Odd bits: Geo name used officially through 97, Chevy is 98 on (not all parts suppliers get it right). Best axles (larger diameter): 97-8, maybe including 96 or 95?
NON-LSI for 98: no cruise control (Audiovox has a ~$100 kit in JCWhitney, don't wire the rev limiter wire; use the agressive gain for acceleration); less plastic; single rear seat (mini van mid seat covers work, but the spit buckets are best all around if you are going to put someone back there; junkyard swap); manual hubs (you will want to replace the auto hubs sooner than later on the LSI); stock wheels are 5.5" (they bend so easy you will replace them when you put wider tires on it anyhow). Some years, the non-LSI has a lower HP engine (I think htere are at least three HP levels stock).
Some years have issues with the engine computers failing (96? on are ok in this general regard).
All Tracker's have daytime running lights for 98 (just pull a pin in the steering column connector and 'poof' it's gone). Later models have the cup holder console (which has a tiny little box in it). Parts that say Suzuki on it are expensive. Chevy sourced can be cheaper. My front seats are reasonably comfortable, though I raised the front mount of the driver seat with brackets an inch or so.
Older two doors have a different top than the later two doors. Go to Bestop and see the differences. I think you can change trim pieces to change top models. The old top side windows aren't removable, where the newer ones are. Bestop makes a fun top for the older one that has a seperate front half (should ahve less leaks, and means the bikini top is always on, but better than a conventional one).
Later units are all 5.125:1 axle ratio in manual trans models. Two slight differences in hoods; not enough difference to notice it if they aren't side by side. Grilles on Chevy/Geo's are basically two in "size": later ones intrude forward if that matters (might if you want to build a tight bumper with winch). Fortunately, crash parts are easy to get from the usual imported (Taiwan) parts places. Someone on Ebay is selling folding manual mirrors (LSI is electric).
4 doors have some (all?) different front end sheetmetal and bumpers. I'd guess that is more to do with front end crash standards. Axles are the same as far as I know. Good source for bigger brakes. Rear brakes on non-ABS models have load (axle to frame distance) sensing proportining valve (at least later ones do). Make sure your insurance gives you the $3 discount for anti-lock brakes. If you lift it, make sure to adjust it (or defeat it) as it wont lock the brakes to pass a dyno based emissions test. Headlights aren't cheap, buy a set when you see them (all older body styles have the same light, but different years ahve different mounting assemblies).
Easiest timing belt I've ever changed.
99 and up have a 2" wider track and rear storage bins, can find a 2 liter engined 2 door a lot easier. Just gear it back to a 1.6 liter and add tires (might be more work to lift, but kits are out there -- no experience on this one). Also have the two piece tops (similar to the Bestop mentioned above).
I really have a good time driving my Tracker -- though my wife says only the driver enjoys it (she rarely drives it, prefering her Forester). Reminds me of my old Honda 600 (remember the old Honda cars?). Power living a mile high is anemic, but as the Brit's would say, you just have to row the crash box.
Mine? 235 AT's, 2" Calmnin lift, custom rear bumper & rack w/hitch, older cross member, 4 door front brakes, wheels, cruise control. 148,000 miles.
