Here is the best advice I can give you:
Instead of waisting $100s of dollars on buying the perfect barrel you can buy:
Freak bore a barrel
Buy the Empire kit (Which is just is the same as the Freak kit with a different name)
Shark Fin kit
Your bore issues will be taken care of with any of these. Plus if you buy the fronts, you can make the barrels different leangths. Smart money either way you go.