If you are looking for a good sealant with longevity, I have had Menzerna Power Lock look really nice, and last longer than Blackfire Wet Diamond, which I also have. The Blackfire Wet Diamond always looks great, but it doesnt have as long a life outside as the Menzerna product.
I Detailed a black Raptor this summer - these things are huge !!! It was metallic black and when finished, the metallic particles looked like you could reach in and touch them.
I used a Rotary and actually use a Rotary on everything and perhaps a Flex 3401VRG or a Meguiars G110V2 for a very light finesse it stage, or applying a glaze or an LSP.
Perhaps if you are going to get a Random Orbital machine, you might want to check out the Meguiars line and their microfiber pads and polishes for Random Orbital machines. They are supposed to be outstanding in terms of correction and finishing quicker than the standard Random Orbital approach of using compounds and polishes..
They should be selling all that equipment here on this site too..
Dan F