Those prices seem a bit steep for buying a bicycle on the internet, if that's how they work. And if you're located in the US - I'm not sure you are, but you did use "$" as a currency, so I'll go out on a limb about that. (And no, just by listing a UK site doesn't mean that's where you are - I order most of my bike odds and ends from UK sites, and I'm in the US...)

And IMO, if you want to upgrade to SRAM Rival, it's best to just buy a new bike with SRAM Rival.

You can get yourself an SRAM Rival build for $1300:

http://www.neuvationcycling.com/prod...rival-1398.htm

That leaves you $500-$900 for a frameset, say like this:

http://www.novemberbicycles.com/frameset/

Then you'd have a nice Neuvation frameset left over.

And if you are in the US, there's always http://www.bikesdirect.com. Their business model doesn't provide much margin for customer service, but since you're posting about moving groupsets from one frame to another, maybe you don't need much help to service your own bikes.