Welcome to SRP.

Any well honed razor that's 5/8 to 6/8 in size should be suitable. You don't want too heavy or too light, and you probably want to stay away from restorations with unusually looking scales, unless the seller has a lot of experience, because the balance of the scales may be off.

In addition to the several UK vendors which I'm sure you're familiar with, I think in the classifieds section of this site many sellers would ship to UK (first class mail is probably less than $1 extra than to US), and from my experience it usually takes between a week and two to get there.