Mr. Van - i'll be the one of the first not to be a dickhead here, and ask what your intending to do with your bike.... ?
The rampage does have some nicer gear on it in certain places, etc etc - but it's still a hardtail, and it's my newly formed opinion that hardtails do suck it on the nasty downhills. Go on all you want about skill guys, bla bla - to me it just makes it painful and detracts from the fun of it. JMO on that one.
I'd say take the dually - go and bargain down the price, whatever - and you can always get a new fork later down the track if your not pleased with the existing.
But if your just hitting up the trails, not hitting up too many drops, and not screwing up too many landings - the rampage might be a fun machine to have.
I'd take the bh sport myself, even if it isn't the best in the world.