Gas tank upgrade question, any makers for us?

Does anyone know of a maker who sells 30-40 gallon gas tanks that fit in the OE mounting location of the <96 ZJs? I've found them for the cherokee but not for the zj's, except for 96+, and they typically require cutting out the floorboard and eliminating the spare tire to accomodate the extra room(we don't have that in our older ones). I'm kinda eager to go up from the 23 gallon to a 30-32 gallon tank, or somewhere around that, but don't want to deal with a fuel cell in the passenger compartment, nor do I want to sacrifice every bit of ground clearance I might be able to gain by dropping it lower. I would however be willing to route the exhaust pipe out the side, maybe infront of the rear tire, if I can cram a muffler in that short span. I'm looking to get something quiter(less obnoxious) than this cherry bomb glasspack in the somewhat near future anyways. If it's another 4" wide, that should give around 28-30 gallons total, so I don't see why it wouldn't fit as long as the exhaust is modified slightly