When and where do you land in the UK? I can point you in the right direction as far as Tickets go.
As for looking round the rest of Wales, I recommend you have a look at Aberystwyth at least since that's a) the largest town within easy travelling distance of Lampeter* and b) the most likely place you be catching the first train (in a series) to get yourself to Edinburgh.
reply to this or email me (I've friended you so you should be able to see my email address now).