Recomended flex plate and torque converter for my 5.9 magnum engine

So...it's a stroker 318, with with a smaller bore and different weight pistons than a 5.9 magnum, but uses the same external weight as a magnum 5.9?

Yes same external balance as a 5.9 magnum

This is the 318 mini stroker motor that FABO member MRL Built