If you have a wide foot, you can rule the Lowndes out - the 348 last is relatively narrow and the toebox will apply a footbinding-like crush to your forefoot. If you like this look, you can get the Seymour on the 337, but will have to order it from C&J in the UK
As noted above, you will fare better with the 337 and the 325 (which has a rounder toe) and the 240, which can be found on sale at Brooks in black or brown perf captoe in a generous E fitting.
The elongated toe makes the shoes a tad longer than you might be used to, but other than that there are only two catches to note on the 337's sizing:
1. to get the right width, all of the typical forum advice on sizing down will likely go right out the window...you may wind up with the same size as your US shoe or going down only 1/2
2. Loafers are a bit trickier than lace ups - apparently the vamp changes the volume of the fit between models
Making a run to the T&A store in either NYC or Beverley Hills is strongly advised. NYC store has bigger selection and the staff is first rate in terms of knowledge and patience. I also spent an embarrassing amount of time in the Jermyn Street shop one afternoon trying on everything and asking all sorts of width-based Qs.
You may find some G fittings work, but these seem to have a ton more volume - for feet that are simply bigger rather than just wider - the Gs I tried on in C&J were like putting the box on. Perhaps an insert might help?
FWIW, I would also advise on shelling out the $25 or whatever it is to buy a professional shoe stretcher. This can go a long way in making an "almost" fit work fine.