WTD – “first” road bike

Hi,
As you may have seen on the main forum I’m looking for a road bike due to a lack of good off-road in my area. I’m 5’9″ish with a 29″ inside leg, so need a frame size to suit that. I don’t like to feel too stretched out, coming from a mtb and bmx background so maybe a shorter TT would be suitable?

My main requirements are:

-relatively comfortable (roads I’ll ride aren’t the smoothest)
-smooth rolling and easily serviceable hubs/bb – no play or grinding bearings please!
-gears that aren’t too worn and still change reliably
-working brakes

Budget is around £300, may be able to extend this a little bit in the coming months though. I’m based in the Northamptonshire area but will drive to pick up for the right bike!

Thanks
Tom