MrSquarepants, Yep I still have the Aquapolis Tyranitar. I'm actually not sure which Meganium you are referring to; if it's the one from Neo Genesis I'm afraid it's already sold. When sending 1-4 cards to the UK, you can use a regular envelope as normal. If it's more than that, you should use a bubble wrap envelope. Anything more than 15 cards and I use an appropriately sized Ultra Pro box. They are basically a plastic box that holds 25, 50, or 100 cards.
Shoot me a PM with details regarding the trade!