Does anyone know what aftermarket wheels will fit a tracker with no caliper interference?  I've been looking at a set of cragar soft 8s or d windows with 4" of back spacing in a 15x7 size.

I had a set of 15X7 AR wagon wheels on our`97 4dr. Fit and worked perfectly. Just went in to the wheel shop and told the guy what vehicle they were for and he ordered them for me. Take a look at Tire Rack

It's around 3-1/2 inches isn't it???

I likeyour choice in wheels, someone has a set in the classifieds or check the below link.
http://www.lowrangeoffroad.com/index.php/suzuki/sidekick-tracker-x90/wheels/pro-comp-rock-crawlers/series-98/rock-crawler-series-98-gloss-black-monster-mod-wheel-pcw98-5885.html

Tuxblacray has a set of 5 soft 8s for sale in the classified section for $200.  They are 8X15.  Good price.  Virtually any tire you put on a second gen truck will have rear fender clearance problems if you go larger than a 30X9.5 or 235/75 series on a stock rim.  So whether it is 7" or 8" I don't see too much difference.  The issue is either the tread width or the series cross section.  

http://www.zukiworld.com/forum/classified-ads/5-cragar-soft-8-black-rims-$200/

I've thought long and hard about just going with used 6X16" Vitara steel wheels and running 215/85/16 tires on them.  30"+ height, 6+" tread width and the full use of the existing stock wheel well.  Sand the rims down, wipe them with Xylol, then spray them Rustoleum semigloss black... and you have some inexpensive "Soft 8s" that you know will fit for a heck of a lot cheaper than buying new rims.  You still have to correct the axle gearing to pull 30+" tires though.  Like:

http://www.tirerack.com/tires/tires.jsp?code=yes&KEYWORD=tires.jsp_Firestone_Destination_M%2FT_Tire&partnum=185R6DESTMT&GCID=C13674x012-tire&tireModel=Destination+M%2FT&tireMake=Firestone&

or

http://www.treadepot.com/tire/B61161.html?CID=21

or

http://www.nextag.com/Hankook-DYNAPRO-MT-RT03-676450522/prices-html

or

http://www.nextag.com/Goodyear-WRANGLER-DURATRAC-1240303312/prices-html

Or

 if you want even more aggressive the original Interco TSL: http://www.intercotire.com/tires.php?id=18&g=1