Thanks for the size advice (& sorry for the lack of inside leg measurement- couldn't remember it off the top of my head). Had a a closer look at the geometry and I've ordered a 56. I've been debating a FM066 SL for a while now but I was slightly uneasy about the possible lack of support- much happier getting this, even though I'm not crazy about the colour scheme (I'd have preferred something darker & more subtle).
5% quidco (£25) and I understand it comes with a BB91 bottom bracket fitted, so that saves another £25 and means it doesn't come in at much more than the FM066 SL.
Totally overkill for me (it's basically my first road bike), but massive thanks for the PSA and I'm looking forward to getting it!