sounds like a nice light you may be building. :)
I will take a serious look into this. Wrap the drop-in? I have never heard of that but it makes sense.
wrapping the dropin is pretty essential with these high-powered LED's which generate a significant amount of heat.
The XM-L will be very bright, but won't be "wall of light" floody. if you want "wall of light" flood, then you'll need either a diffuser or something like an MC-E, SSC-P7 or a SST-50/90 dropin :)