Your '98 has an AX-15 transmission, the NV3550 didn't come along until 2000.
Clutch-wise, I would only go with a Luk OE replacement kit, and avoid Centerforce. Centerforce clutches are designed with centrifugal weights that only help hold the clutch tighter at very high rpms. They are not a clutch that was designed for the typical uses a Jeep sees and they are WAY more expensive than a better suited clutch like Luk sells for. Despite their heavy advertising making them seem like the right choice, I strongly recommend against a Centerforce clutch for a Jeep Wrangler. Luk is the OE manufacturer of the TJ's clutch and most go well over 200K miles before needing to be replaced. I repeatedly smoked my Luk clutch with years of rock crawling and when I pulled it to replace as a precaution before doing a major rock crawling trail, I was amazed that with over 167,000 hard miles on it, it was still in great condition with at least another 20-30K miles of life left on it. I stayed with Luk with the replacement.
Here's one photo of one of the many times my Luk clutch got smoked and survived with no problem... the Gatekeeper opening to Doran Canyon in the deserts of SOCAL, near Calico Ghost Town. Yes, that smoke in the pic is from the clutch.