Couple of sora equipped felt bikes under £500 at wiggle.
http://www.wiggle.co.uk/felt-f95-2015/
http://www.wiggle.co.uk/felt-z95-2015/
http://www.wiggle.co.uk/felt-f95-2015/
http://www.wiggle.co.uk/felt-z95-2015/
http://www.decathlon.co.uk/triban-500-se-road-bike-black-id_8306187.html
Triban 500 SE for £299! It's what I've got and it's a great entry level cheap road bike. Microshift + carbon fork
As i say, it's an alright bike but you're generally much better off with a Shimano groupset, the Merlin is a much better buy if you want to stay at the lower end of your budget. Road bike size is based on inseam and reach, not height. That said, it is generally a better idea to go smaller rather than bigger because it's much easier to compensate for with saddle height/stem length.
http://www.wikihow.com/Size-a-Road-Bike
Of the two I'd definitely go for the 520 - Sora is going to be a big improvement over microshift.
Carbon fibre brakes....?
As I think was mentioned above or in one of the other posts (I've lost track sorry), microshift does the job but the smoothness of the shifting will be better with sora levers. For the minimal extra it costs I think it's definitely worth it.
edit: I think I'm tired. I'm not even sure where the 520 was linked to any more, sigh.
You'll enjoy it
And in a year you'll be agonising over an extra grand on the next bike you buy
Easy there tiger, I'll be in my third year of uni, and i have bills,rent to pay, and Europe to travel for dnb festivals!