Mountain Biking - Opinions on this drivetrain

Since I cant save enough money to get a new bike I decided to put some new drivetrain parts on my avalanche to amke it a little more competitive. I was planning on getting Race Face cranks and BB with Sram chain and cassette (links below). Is there anything else I would need? Also would my shimano 7 speed derailures work with the 8 speed casette and would the hub i have now still work?
http://www.jensonusa.com/store/product.aspx?i=BB708C01
http://www.jensonusa.com/store/product.aspx?i=CR602A00
http://www.jensonusa.com/store/product.aspx?i=CH707A00
http://www.jensonusa.com/store/product.aspx?i=CS708B16

PS: I was just wondering if I wanted to upgrade rims and hubs later what hubs would go good with rhinolytes?
http://www.jensonusa.com/store/product.aspx?i=RI707A12

A new wheelset would likely make a much bigger difference in your riding than a better drivetrain. Shimano XT hubs/Rhynolites are probably a good choice for general riding, although the XT rear hub tends to break down after a while. I personally have not had problems with my 3-year old XT hubs.

The crank you linked to is the new X-drive version so you don't need an ISIS bb. With that in mind DON'T buy an ISIS crankset, ISIS bbs are the pits.

What do you mean by competitive? Are you racing? If so and you don't weigh more than, say, 190lbs I'd look into lighter rims than rhinos.

Also, upgrading a bike is a lot more expensive than buying a new one in the long run. Here's a realy nice bike for a racer on a tight budget: 2005 Kona Caldera (http://www.konaworld.com/shopping_cart/FrontEnd/Products/product_detail.aspx?productid=91&parentid=182) although it has one of those pesky ISIS cranks. ;) By the time you add up all your upgrades I bet you're at 1/2 the price of the new Kona, and if you buy the new Kona you have a good backup bike for commuting!

ISis bb's the pits. Sounds like someone is buying into the proprietary marketting. FSA's are fine for 90% of the riders out there. Heck I bet square bb's would be fine for most. Nothign is perfect and so far x-type isn't getting amazing reviews either with non drive side crank arms falling off. Nice thing about isis is the abiliy to interchange and move stuff around. As far as I have heard you have to set and forget x-type of bad things start happening.

Did you know fsa is making an outboard bearing fsa standard bb. No need for proprietary parts with all the 'extra' of outboard bearings.

No I'm not buying into marketing hype, ISIS sucks for XC if you don't want to replace bb's religiously, the bearings are just too small. That said, I'm not jumping on X-drive either, I'll stick with my square tapper NEXT LP's for as long as I can.

Edit - the major problem I see with X-drive and (probably worse) the external bearing ISIS from FSA is the wide q-factor. Little people like me don't have that wide of hips.

No I'm not buying into marketing hype, ISIS sucks for XC if you don't want to replace bb's religiously, the bearings are just too small. That said, I'm not jumping on X-drive either, I'll stick with my square tapper NEXT LP's for as long as I can.

Edit - the major problem I see with X-drive and (probably worse) the external bearing ISIS from FSA is the wide q-factor. Little people like me don't have that wide of hips.Personally I use a Truvativ Gigapipe Team DH four sets of bearings no problems in the year I've had it in there.

hmm, well from what ive seen from reviews Race Face BB's are complete crap, that steered me from buying one. I have no problem with ISIS, get the BB like raiyn said, the one i have i picked up for 65 on ebay and it has 3 sets of Ball bearings. A setup i have for XC is:
Token ti BB
Truvativ Stylo team
SRAM x.7
PC69
PG-770 cassette
im in highschool so im on a budjet with a 6$ per hour job :) but that systems been working out well

Raceface had one 3month period of bad bearings in 2003...they have never lived that one period down. Raceface bb's are fine.

By competitive I meant I want to make it more durable because Im starting to ride a little more aggressively and my stock parts just dont keep up. Also weight isnt a matter to me Id prefer durability over weight. So if I understand this right the Race Face cranks are fine but the Race Face BB is uneccasary at this time and all the other things should work fine?

I have almost two full seasons on a race face ti bb. Other then re tightening the cups once or twice a year I have no problems with it. still goes good.