Depends on which P-51 and which P-47 we're talking about. Everyone almost always is referring to the P-51D and most talk about the P-47D. The max range for the P-47D was around 1800 miles while the P-51Ds range was around 2300 miles. The P-51D's top speed is listed to be around 437mph @ 25000'.
The P-47N however had a range of almost 2400 miles. This version escorted B-29s all the way from Saipan. Plus its listed top speed was 448mph @ 25000'.
The M version was basically built just to intercept V1 buzz bombs. It was lightened and had little armor, included water injection and was fitted with airbrakes. It also had no external hardpoints.
Dont forget the XP-47J was the first propeller driven fighter to exceed 500mph in level flight.
I have read that the R-2800's could be turned up to very high horsepower levels, like around 3200hp. They did wear out sooner but didnt suffer any failures at all, just a shorter TBO.
My preference (my choice, meaning its my view whether consitent or inconsistent with others views) would be the P-47. Later versions could do what a P-51 could do plus some and have the big radial engine up front, you cant go wrong with that. (Though sincerely deep down, I always wanted to be in the bombers)
Fighter pilots make movies.
Bomber pilots make history.