got-to-get-fit said:
The RB1 got an excellent write up in a previous Cycling Plus Magazine article, well worth a look if you can find a dealer/distributor.
As for the Giro 200...
Have a look on Dawes website and if you can up your budget and get a Giro 400, you'll be less likely to have to upgrade bits shortly.
As others have pointed out low cost generally indicates low/poor quality.
This time of year plenty of shops/distributors are looking to off load 'last years' models i.e. 2007/08, usually the only significant difference will be a paint job, maybe a bit of trickle down componentry improvement.
Visit your LBS Local Bike Shop and see what they can do, ride some different makes/sizes and see which feels the best, if it comes down to a couple of bikes go with the one your heart tells you (providing of course it is perfect in all other aspects)