I'm looking at taking up cycling primarily as a way of commuting to and from work 15 miles away but with the intention of joining a club and cycling all year round. My employer is currently taking part in the Ride To Work scheme with Evans Cycles and so i will be looking at purchasing from them, however, i'll be honest and admit i don't really know what i'm looking for. I have a budget of around £800 and have noticed there appear to be a lot of discounts to take advantage of on previous models. The manufacturers i have been looking at include Bianchi, Cannondale, Felt, Le Monde, Trek and Specialized, however, i have heard that some manufacturers (ie. Bianchi) are more suited for cyclists who are slightly smaller. In adition to this i'm interested in finding out the main differences between Campagnolo and Shimano 105, Ultegra and Tiagra. Obviously i'm looking at getting the best bike available for the money i am looking at spending but could do with some advice from those in the know. Thanks in advance.