I'm also in England and I use Tesco organic maple syrup. It's not too expensive. I also buy organic lemons from there too- you can buy packs of 4. The tea I use is from Holland and Barrett health food shop and is called Slimatee- senna and frangula. You can buy packs of 20 or 10.
I don't find that the salt water flush fits in with my life- I'm a school teacher and I can't leave the classroom to dash to the toilet, so I drink the tea both at night and in the morning. You might find this helpful if the salt water flush doesn't agree with you!
I'd also recommend halving the amount of maple syrup you use in each cup- it will help you lose more weight and I also find the taste better!
Good luck, Claire