Rapid fire or Grip shift?

[aquawife]

On my last two mountain bikes I had grip shift for my front derailleur and rapid fire for the rear.

Haha! I had lunch with my husband (just got back in town after being gone for over a week) and was asking him what he thought of the whole shifting thing since he's ridden them both. He said that he like the grip shift for his front but liked the precision of the rapid fire for his rear. I emailed the bike shop guy and said I was thinking about doing this. Bike shop guy will do anything I ask so that's not an issue. Also, if I decide to be daring and try the grip shift and don't like it they can always switch it out.
I'm not sure I like the idea of the dual control. One, it just seems weird - although I'd probably be just fine after a few rides. But two, I am trying to contain costs a little bit here and buying XTR dual controls isn't really where I'd want to spend my money.

Someone asked to tell about my bike. Okay!!
Specialized Epic Marathon frame in PINK!!!
Pace RC39 fork (carbon legs - very sexy!) (a UK fork - light as a Sid WorldCup but better - and cheaper too!!)
Spinery Xcylone wheels - white rims and spokes!
Magura Marta brakes
And then I'll be transferring my Chris King, Thomson, and carbon monkeylite bars and my derailleurs.
I haven't found out what my crankset will be. I think that's the surprise that bike shop guy told my sister-in-law not to tell me - I can't think of anything else major that needs to go on the bike. (The bike shop in 4 hrs away where my SIL lives so I'm doing things by email and having my SIL pester). It's actually easier that way! I highly recommend having someone else be the pesterer!
I won't get the bike though until after Christmas. Once I do I'll do another post and brag about what a sweet ride it is!
Thanks for all you input!!

Update: the bike shop guy just emailed. He thinks the two different shifters is a great idea. He's seen it on some pro bikes. In fact, he likes the idea so much he's doing it to his bike right now!! Who knew I was a genius?!