[wmab]

I use Daysoft [1], they're their own brand of contacts, but by the inventor of the daily disposable, and I've used them for years and have been great. They're UK based so all you're required to do to "prove" prescription is check a box. No need to submit anything for prescription (since this isn't required by UK law, there's nothing to stop you buying contacts from anywhere in the UK). They're also <$20 for 30 lenses.

[1] https://www.daysoft.com/