Too ricey? You're f'ing nuts.....GREAT resonance inside the cabin, sounds pretty good outside too, perhaps not as reliable as I expected but then again, I'm a very aggressive/hard driver, especially off-road. The only design problem with the Borla is it's a little thin, but unless you have a set of headers to go with it, you're not gonna notice the lack of diameter (2" or 2.125" I think). You will, however, get a VERY nice and mellow sound (stainless steel), and some extra performance on top of it.
I'd also recommend a header and a high-flow cat. You have 2 O2 sensors - 1 in front of the cat, the other right behind it - so, unfortunately, you cannot simply drill out the catalyst, or else the second O2 sensor will go haywire.
Clifford still makes dual-outlet headers - 1 header for every 3 cylinders - and I don't know about the reliability (I imagine they must be pretty good), but you'd have to either bend some custom pipe yourself, or have somebody do it. Nobody makes a true dual kit for the XJ, but there's plenty of room for them if you feel so inclined (as I do).