Blah, your new bike looks fantastic. I've been on the look out for just such a frame and I think you've found it for me - thanks!
Could you fit a rack and panniers on the back of it without your heels clipping the luggage? The chain stays look long enough.
Thank you
There are no braze-ons for a rack, even though I was expecting them. Just looking at the Ribble site again, it's only the horizontal top tube version (which takes normal as opposed to deep drop brakes) that has rack lugs. Interesting that, the version designed for narrower tyres takes a rack...
In any case, you could do it with p-clips. I'm not sure the stays are long enough, this all depends on your shoe size, where you put your cleats on your shoes, and the position of and which luggage you plan to use.
In terms of handling, it's actually a pleasingly sporty number. I don't think you'd want to put a lot of weight on it, and if you were to do so, I'd go down the Carradice saddle bag route.
For me, I'll treat like a racing bike, but with mudguards.