DA gum ....

LOVE IT ! ! ! LOOKING GOOD ..... [8D]

What size nitro ? Well , figure if your planning on using a weedie engine , OR nitro , just convert the nitro engines size to match the output of the weedies prop .
Meaning - if the weedie you want to use , will push a 16X10 tri pusher , then the nitro should match it - like the one HAL , or myself done - around a 1.48 engine ( nitro )
Also aauming you are talking 2 strokers and not 4 stroker nitros .
Weedie's have the torque , whereas the nitro has has the HP . So , what you loose in HP , with the weedie , is where you gain the torque , which is why the same size prop is used

Anyway ... the smallest I would use for a hull that size would be a 90 and the largest - around a 1.48


Think of this also . Whatever size engine you would put in it if it were a water prop driven engine , that is about the same that you would use , for an airboat size hull . ( roughly of course )