I converted my Tiger-60 (kit built by other) to a tail dragger. The best you are going to do on the mains is to put the mounting block as close to the leading edged as you can, which has been pointed out by others will leave your wheels sitting 3" in front of the CG. Reinforce with tri-stock. Make sure nothing interferes with the operation of the hold down dowels, including the bolts that secure the landing gear to the fuselage (don't ask me how I know!).

As far as mounting the tail wheel goes, the sheeting on the bottom of the fuse near the tail is balsa, at least on my plane. I added a two inch long piece of 1/8 birch plywood to distribute the load "just in case". I treated myself and put a sullivan tailwheel assembly on the rear (it connects the tailwheel control to the rudder via a spring). Probably overkill, but it's piece of mind.

I have 2 3/4 inch wheels up front, and a 3/4" wheel on the back. If you fly off of something harder than grass, I'm sure you can get away with smaller wheels up front.

BTW, this plane looks really nice set up as a taildragger.