I can add some input here, as I'm wetsanding my 5.0 right now. it's black too.
The previous owner took it to a 'backyard paint shop' someplace, and there were bugs and orange peel galore in this thing. I, of course, didn't know that, cuz I bout the car at night. (stupid)
Anyway, I'm wetsanding with 1500 (NOT necessary with just swirl marks, always try the least aggressive and work your way up), then hitting it with cutting creme with a good strong buffer. Then, hitting it with swirl remover and a polishing pad. I'm taking my time, and am VERY pleased with the results. It's turning out very very well IMO. Just using some Meguir's NXT wax after that's all done to protect, and I have no scratches/swirls left.
I would try swirl remover, if your buffer is fast enough- Not enough RPM's and it won't work.
Also, the stock clearcoats are thinner generally than aftermarket paintjobs, because the factory puts on only as much as they need to. So, I would not recommend wetsanding/cutting a stock paintjob, unless you're VERY gentle, and have some experience.
I don't know the brand of the cremes I'm using, and I don't have pics yet, but when I do, and if you're interested, I can post them.