Cardiff area
Hi and welcome! Yes, I am in Wales, too! I'm about halfway between Llanelli and Carmarthen. It's a bit of a drive from here to Cardiff, but almost completely M4, so it's easy driving.
There are a LOT of Americans in the Cardiff area. There's a Facebook group for them. I haven't gone to any of their meetups, yet, because I only just got myself mobile last month (after 5 years in the UK!), and the FB group aren't UKYankee forum people.... I'd be all over Cardiff already if this group was there!
But YOU are coming, so maybe I'll stop being so clique-ish once you arrive... after all, you're part of UK Yankee, now!