BEST T/CONVERTER TO USE

[mr m]

Hi fellow moparers
the new built 505 RB needs a converter and plate , having it bench dyno'd so will get the figures for the converter spec but who do i order from?
Does it have to come from the states or is there a reputable firm here. Will be mainly a street car but will hope to put it through its paces occasionally
have been advised about 2500 stall,
any suggestions welcome