Build it stock first.

Do modifications when you do repairs.

Resist the temptation to over power it at first. An old OS FP 40 will hall a Sr. around. You can always upgrade later.

Don't let the stick framing scare you off. A razor saw and a sanding block and you will be cutting cross braces and stringers like a prow.

On the down side the Sr has rubber bands. They suck to put on but they do minimize damage in case of a mishap. This is one of the things you can modify later.

The great thing about a Sr is it renders it self to upgrades as you learn. If you think that a tail drager or floats might in its future you might put in extra hard wood blocks.