I drilled a non RR 100g and am happy with the results. The glass-holes kit is a good way to go, but you can find less expensive kits that will do the same thing (search on eBay).
Drilling the tank is really not difficult at all, just be sure that the glass you are drilling is not tempered. I drilled my overflow drains, and just ran the return line over the rim of the tank. It is not too noticeable, and saves you putting another hole in the back glass.
Good luck!