Well...took the plunge and ordered some XM-L's and a DIM4 controller. Also grabbed a driver to have the option of really seeing what the XM-L's will do. Really looking forward to the DIY, just need a heatsink or some alu. u channels.
If it's not enough light, and I doubt that will be the case, I can build it for my 13g and swap the T5HO.