First Fixed Gear Build

I didn't put to much thought into that and now I feel like an idiot. It's 124mm so hopefully I'll be good.

I'm not with the bike at the moment so I have no idea, I was more interested in the headset anyway so it wouldn't be hassle to change the BB if needed. I'm pretty sure it'll be fine though.

and yeah, it's 144bcd (well advertised as anyway). Nearly picked one up for £130 a few minutes before i won this one (it was a single but whatever)

I bought the same wheels for a friend and needed them re-dished once I'd spaced them for a 130mm frame: they come set-up for 120mm.

Judging by the position of the rear derailleur cable guide, your frame is likely to be 126mm, so you might get away with it by tuning the chainline via the bottom bracket.

However, you've bought road double cranks and already have a bottom bracket, which limits your options somewhat. Is the bottom bracket the recommended width for those cranks in a double set-up or shorter to bring it inboard for a single ring?

You have the option of running the ring on the inside, but it doesn't look like 144bcd (damn good buy if it is).