The wheels look good and should be strong and durable if they are tensioned properly. You might keep a couple of £'s available to pay a good local shop go over them for true and tension. Many machine built wheels are lacking somewhat but can be very reliable if touched up before they are put into service. Going to 135 mm OLD is a bit of overkill but can't hurt.
The chain, cassette, and rear derailleurs are also good choices, particularly at those attractive prices. I assume equivalent 9-speed items would have been significantly more money.
There are shims that will allow a 35 mm clamp-on front derailleur to fit on a 28.6 mm seat tube but they are a kludge and may interfer with the shifting. Front derailleurs, even good ones, are realtively cheap so get one with the right size clamp. You can either buy a clamp-on fd with a 28.6 mm clamp or a braze-on fd and a proper diameter adapter clamp. At worst, you now have a £0.99 paper weight.
You didn't mention shifters. What did you decide to do about them? 8-speed bar end or downtube shifters should still be available and at reasonably low cost. 8-speed STI (integtated brake/shift levers) are also available but are significantly more costly.