Folding Fabric Sunroof

Has anyone ever installed one of these folding fabric sunroofs manufactured by "street beat customs" (like on old VW's or Mercedes) on their XJ?

http://www.streetbeatcustoms.com/ragtopsunroofs.html

I'm interested in installing one as large as possible, but am worried about the structural integrity of the vehicle....I haven't been able to find any specific info on number or location of any beams in the roof of the 1999 xj. I don't drive offroad. If I do remove a large section of roof, would a rigid bolt on roof rack add back some structural support? Please post pics if you've done one of these and any installation advice.
Thanks for any help.

there is a beam right above the B pillars, right behind the front seats. If you have a 4 door, there may be one there also. I havent seen a 4 door with no headliner in it.
If you dont leav the pavement you will probably not have to worry about it much. Allthough you will undoubtably notice less rigidity in it. Plus im not sure how well it would handle in a roll-over.I have a glass motorized sun roof i nmine above the front seats. It was put there by a P.O. and i like it. but the beams are the part of the roof you need to worry about.The sheet metal roof isnt that important towards stability.Mabye putting an off-road safari type rack on the roof would help re-inforce what was lost with the removal of the beams, i would think you wouldnt want to place a rack above your new rag-top, it would kinda seem counter-productive.
Give it a shot!!! Everyone should try something different.

i was lookin for a sunroof too. where did you get yours ans for how much?