Creatine mono is the best one to get mate, its cheap and i have found it to be very effective.
creatine helps with everything from ATP replenishment, improved rest, protein synthesis... so so many good things.
I would be silly of me to write it all down, but they have at
http://www.menshealth.co.uk/chatroom/top… this article gives you everything you need to know about creatine.
and just to answer all your above questions in a quick fashion incase you dont have time to read the thread on the link (though i suggest you do, its a really good read):
mono is the best to take.
cheapest whey is pretty much the same as expensive.
creatine will definately help you from what i have read about in your other questions, however it does cause water retension and so you may see a small gain in weight from that, so might be better to bulk first before trying to lose the fat.
Though it can be used for everything, i would start bulking first.
If your just starting creatine i really would look into just taking mono for now, the cheapest on on myprotein.co.uk
the best protein supplement is standard whey as it contains loads of essential proteins and is cheap as chips, though i think i already responded to one of your questions asking that.