Fitting an F/C to a PT Super 24 base? Thats exactly the opposite to what I have done. My PT on a FC base seems to work well. Been going a few months now but not much growth during winter. Its quite a bit of work I found fitting these non standard motors to these bases but I'm sure its possible. My PT is fitted crossways like all PT's except those on 24's. I can not see that that makes any difference.
Its a pity we are not closer. I would gladly swap bases.
I still think that Suzuki would be worth a try. As you have said I do not think the power is much of an issue. Its the blade spimming mass that matters . Good to hear you are well to work even if it is on a Briggs.