The Will hobby P-51 60 is the exact same as a Hangar Nine. In fact, it comes with the Hangar Nine instruction manual.
Can be purchased for under $100 vs $254 for the H9.
Jerry Lu is the US distributor and I got mine from him for under $100 (shipped)
Here's Jerry's e-mail: firstname.lastname@example.org
There are a few differences though:
1) The retracts and wheel-wells are not pre-installed like H9 (which is nice because you can re-enforce inside the wing where the gear mounts before installing the wheel-wells) I consider this to be a plus over the H9!!!
2) The retracts and wheel-wells are not good quality and I did not use them. The good news is that you can buy new Hangar-Nine Wheel Wells from Horizon hobby for $7.99/Pair. (and they fit) So, it's no big deal!
3) The color scheme is different and I like it better than the H9 (gotta love those invasion stripes).
As with most of today's ARFs, the hardware bag should be thrown into the trash barrell!
For the power plant, I used the OS91 SurpassII with a Keleo creations exhaust (yes those are functioning exhaust stacks)
It flies better than it looks. It tracks really nice and has no bad habits. This is a real bank and yanker. On landing though you gotta have the engine idle way down or she just keeps on flying.