I know the model in question pretty well and its very well powered with a pair of zenoah 20's. i have also seen them flown with lader 150 four stroke glows and it went just as well if not better, and sounded awesome. to be fair i think your engines are a little big as yellow aircraft suggest similar powerplants for their 100'' P38.

Either way, inverted would be my choice as it makes cooling easier.