gcam,
Unfortunately, most of these replies are not answering your original question.
They are, however correct in that "better" cages can be bought and built cheaper, but those kinds of cages are more intrusive to the interior, limit access to the dash, and are not easily removeable.
I have personal experience with the rockhard cage and for all the reasons you mention, it would certainly fit your needs. It is not a bad cage at all and I wouldn't hesitate for a minute to buy one for my own daily driver / moderate wheeling rig - if I had one. I would not recommend this cage for the hard core rigs - which is what I have. Many guys put the cage in to do two tasks - protect in a roll-over, and to provide unibody strength. The rockhard cage will do very little to strengthen the unibody because of the clamps - compared to a welded, triangulated cage.
My best friend had the oportunity to have his '89 2 door be the test rig for their prototype. The owner needed a 2 door XJ to build the kit since all he had built at the time were 4 door kits. I hauled his rig there and back to Nebraska where the kit is built and saw the manufacturing process. It's a very well built kit for a bolt in cage.
One of our guys here in Colorado - planefixer - had a weld in cage that failed dangerously when he was involved in a front impact accident. One of the tubes broke at the weld joint above his head at the b-hoop. Coulda really hurt him had his head hit it. The rockhard cage wouldn't have come apart like that - sure, the clamps might move on the bar, but I don't think it would come apart. I've heard others be critical of the steel plate design used for the A-pillar area between the dash and door. Concern for knee injury in an accident because of the sharp edges. I've sat in my buddy's rig and it really isn't much of a concern - they're a long way from your knee. The other critique is that the 1/4" plate would bend or buckle during a roll. Yeah, it might, but not easily and certainly is way better than no cage and watching the A-pillars and roof come folding in at ya. Something to think about.
There's going to be a whole lot of opinions about the pros and cons about welded and bolted cages, but I think the rockhard cage is certainly better than no cage and is a well built unit.
If YOU are ok with the price for what you need a cage to do, then I say go for it. I can't imagine you'll be disappointed.