The easiest way is by far using the Omega's, and that's likewise usually the best option since they're tweaked to run graphical games and apps really well. They also come with some nice overclocking tools, incase you want to use them. The downside to that is that it usually take them a week or two to get their versions released after a new catalyst comes out, so you have to wait a bit.
DH Mod works nice too, in that it will alter the files to run for you, so you can get the new cats right off the bat. They don't have any of the nice tweaks or bonuses though.
Self install is probably the most aggrivating, since you have to do it all yourself, and if you don't know what you're doing, you can screw it up farily well.
I'd just wait for the Omegas, if I were you. Go ahead and go get the ones that are currently out (the Cat 4.5s) and use them until the new ones come out.