Personally Si, I wouldn't bother. You've not got the buying power of the big boys anyway, so it will be hard to compete on price. That and as any good businessman knows, cash is king!
Seems to me you'd have to tie up a lot of capital buying up SRAM groupsets (which would instantly alienate me too) which quite a few would probably then end up laying about for some time. And you'd not be making the kind of margins you do on the SRAM stuff as you do on the frames you sell (reseller margin Vs importer margins), so you'd be tying up more money to make a much smaller percentage profit.
If I were you, I'd offer the facility for a custom build to any customer at the price of the parts on top of the frame plus maybe £50 to build it all, as this may attract more customers, and though you might lose out on a bit of margin, you wouldn't have to tie up so much money on components not everyone is going to want!
The way I see it now is something like this... You sell a frame for say £500, it has probably cost you £200-250, so you make a good profit on it... You build that £500 frame up and sell it as a £1500 bike, and I'll bet the £1000 worth of components and your time and effort has cost you even with trade prices, in the region of £750-800. So you can make another £200-250 overall, but it has cost you another £750-800 to do... Not good maths in my book!
Keep your inventory low, your cash flow high, and major on flexibility that is the key. In your position I'd rather be selling frames and offering custom builds on them (with little or no profit on the parts) than holding lots of inventory many people might not actually want... You seen how much stuff gets sold on eBay by the likes of ATB sales et al that was bought to fit last years bikes, but never actually got sold, and now is fetching a fraction of it's original price? I've bought £120 carbon bars for £50 that way, £500 forks for £175, the list could go on...
On second thoughts, buy a load of Shimano XT and Easton kit, I'll probably be due a new drivetrains and bars/stem/seatpost next year, and will be able to pick it all up cheaply from your wholesale end of season sell off on eBay!