Thanks for all the input, guys.
After much deliberation, I've decided on the plow handled grip. The saw handle may give a bit more stability, but some competitions don't allow them, and many gold medals are won in international competition with the plow handled pistols. Also, if I'm being honest, I never really liked the looks of the saw handle pistols.
I will make some mock up handles to see what fits best, but it will be something like the LePage, Probin or a Purdey pistol.
I have the locks and barrels sourced, now I need to figure out the hooked breeches and find a steel spur triggerguard. I just ordered this fine looking trigger for the project from Larry Akers on here, and I have a nice chunk of English walnut waiting in the shop.