Well here's my two bob's worth
Fleabay is (mostly, though not entirely) poor value for dive kit, especially if, as a beginner, you don't yet know what's what. Buying new, at least via the internet, can actually be cheaper than fleabay in many cases.
One exception - a BCD from fleabay for between £50 & £70 is a good start. You can sell it for little or no loss if (when?) you buy a wing, or even if at some point you want a more bling BCD for some reason. Sizing for BCD is basically small, medium, large. And providing it doesn't have a leak in it (ie does it is stay up overnight), and the inflator doesn't leak air into the wing - (does it inflate overnight if fixed to a cylinder), then you are good to go. For the record, I do have a wing, and made a slight profit selling on my original 2nd-hand BCD
Regs - many, probably most, regs are fine - but want "cold water" rated ones for UK eg Apeks "40" models and upwards.
People say, "get good regs as your life depends on them", and whilst this is in a sense quite literally true, it's not the point. Apeks 40 or 50 (whether TX, ATX, XTX or whatever) are genuinely excellent regs albeit ridiculously cheap - not a phrase usually associated with any diving kit. I have a mixture of Apeks TX40, TX50, XTX50 & some Poseidon Cyklons, and though I do slightly prefer the (considerably dearer) Poseidons they're not actually "better" in any absolute sense. There is simply no need to spend more. A Rolex won't tell the time better than a Casio nor be as reliable, although some may prefer the former for "bling" reasons.
One piece of (very good) advice I was given, and now pass on, is don't get a console, even if in a special deal job lot. Just get a pressure gauge, then put compass & computer on your wrists - much neater and easier.
I agree with earlier posters about snorkel - don't stick it on mask, nor or your leg were it'll surely catch on something. That said I do have a folding one in my pocket to help in the "lost at sea" scenario.
Drysuit - I think someone mentioned O3 - extremely well regarded, though I've not had one myself. Mine's an Otter from Bradford and I'd definitely buy another next time. If much cheaper than Otter, I'd be a little wary though. Whoever you buy off, if ordering in, I'd be measured up by the makers even if it means travel. I'm not sure I'd be keen on a "lesser" make if that's all your local shop had. There are other good makes than the above two I dare, but you'll need to do some homework.
I'd also read the DIR fundamentals book. Although by no means DIR myself, albeit I am somewhat influenced by it, I found it a great start on configuring my kit as the mainstream organisations are very vague on this kind of stuff (PADI & BSAC alike). Bear in mind some of it is a bit American and can be ignored (burst discs on manifolds), and upstream and doesnstream reg types etc is not something you need to worry about overmuch if you buy Apeks say). Also read up about the "long hose" thing - but unfortunately BSAC are pooey about this on courses at least - for some apparently secret reason (sorry couldn't resist).