I built my BUSA Cub using an x-acto knife and razor saw, c-clamps, and a band saw. Pins were used to hold parts to the building board. Soldering is required, if you use the kit supplied landing gear. A dremel tool is always handy in any build. Mine is covered with Solartex, so a covering iron and heat gun were used.
I was using these same items 20 years ago. LOL
For an engine, a 1.60 to 1.80 glow twin would be awesome. If going gas, I suggest an engine with a rear carb and rear exhaust. This will reduce the amount of cutting required to fit the cowl.