I used to swim with Camden Swiss Cottage, and only left them when I left London. They're based in Swiss Cottage (so a short hop on the Jubilee line for you) and there are morning, evening and weekend trainng sessions.
I had 3 years off running due to PF and am only now beginning to recover. Most effective for me at reducing the pain has been night splints with ice packs stuffed in under the soles of my feet. Calf and hamstring stretches seem to help with the tight muscles which helped cause it in the first place. I'd agree with Little E that its helpful to try to identify a cause or trigger if you can - like you say, its not something you'd want to go through twice.
I use Keifer prescription goggles (about £20 from SwimShop) for training, if you want another prescription option.
Otherwise, as someone else has mentioned, the best way to see which shape fits best is to try them in the shop. I was told to do the following, which has worked for me: Push the goggly bit on to your face until you get that very slight suction feel, don't put the strap round the back of your head, look down slightly and see if the goggles stay on for a bit. If they fall immediately they probably don't suit your face shape and so probably will leak. The ones which are the better fit should stay on for longer.