If you've got the money to blow, I'd definitely splurge on the tea you love. I'm a PGTips lover and while I can find it in my grocery store, I pay for the privilege. I also love plain old McVities Digestives and a lot of the other 'biscuits' so I'd probably send over a bunch of those. I'd also buy quite a bit of Cadbury - not so much for me, but for my family who love it.
Aside from that, the things I miss can't be shipped so easily (cheeses, sausages, M&S stuff) but I've found good substitutes!