FS2004 Newbie's Question

Hi All

I am trying to finish the F4u-1 Birdcage payware I have been working on since Ronnie bowed out of the project. While working on the custom sound files I checked the stock sound folder and found that Ronnie had simply aliased the sound to the stock DC3 sound file. For a payware project that does not seem ethical to me. So I am now working on a new sound folder for the aircraft. I have been experimenting using sound files captured from youtube videos of the F4u but being youtube copyrights belong the video producers not to me so I cannot use them other than for experimenting.

Now to the question does anyone know where I can buy licensed radial engine sound files?
I have checked at the Soundrangers site, they have a few dc3 engine sounds (a fair approximation of the f4u's engine) but not a lot.

Check out (in no particular order) Adam Murphy of Skyhigh and Tufun at Sim Outhouse (see d/l section Sounds). They have P&W 1820's and 1830's, would these be appropriate?
The F4u-1 used the P&W R-2800 I could modify and mix 1820's and 1830's to useable files... I think. But Tofun's package is freeware and modifications of original sound files created by Gary Jones. I am looking for commercial use licensed sounds.