Im not sure if the clock speeds will save under profiles as well, i can't see why not though as you can have different fan setting profiles, so its worth a try.
All you do is set all your settings first (AA/AF, clock speeds etc...), then go to the Profile Manager and give it a name, make sure at the bottom (in the This Profile Includes bit), that you have All Catalyst Control Centre Settings selected, then save it, then just repeat the process for your next profile, go and change all the settings, give it a new name, save, and just repeat for as many profiles as want.
You can also use ATi Tray Tools instead of the CCC to do the profiles, as that does them exactly like Nvidia's do them, but im not sure if you can do clock speeds in that as well though as ive never used it.
Can't really see it doing much harm underclocking the speeds tbh, just overclocking, as that will shorten the life of the card obviously, and depending on how far you push break it.
