The guy that said avoid pedigree breeds, lol....
OK, 9-5 and not home at lunch? Why even bother having a dog? It's not nice, even if the dog can physically go 8 hours with no accidents or much care it's still not fair on the dog as they love their owners, so if you can get home at lunch seriously make this a strict routine and go with it. Consideration for dogs lifestyles has seriously divebombed the past decade and that saddens me as there is more dogs now in homes than ever and we know for a fact a lot of these humans shouldn't have them. Just sit down and think about it carefully from a dogs perspective before you commit and ensure you'll always put the dogs wellbeing first over 9-5'ing.
Insurance, I am £18 a month that is lifetime cover on a VERY good policy for my older dog (6). You can get it much cheaper, tenner a month, but not worth the paper it is written on.
Vets, most do puppy packages so your 2 vaccinations, microchip and worming for first 6 months. Typically £100ish. From there it is worming/flea treatment and a booster each year. Not expensive at all as spread out throughout the year.
I always recommend sight hounds to people in your situation. 9-5 worker who will walk twice a day minimum. Greyhound, Whippet (what I have), Saluki and to an extent if you want a properly small dog, Italian Greyhound although not a sight hound share a lot of traits with sight hounds with some added loopiness! Sigh hounds are extremely lazy, 18 hours sleep a day type lazy and 2 decent walks a day will see them come home knackered, no need to walk them for hours on end 3 times a day. Whippets are 35mph sprinting couch potatoes who will cuddle you to death.....
I would always discourage people in your situation from getting something like any form of Spaniel or Collie. I have grown up surrounded by spaniels my entire life, I simply wouldn't have one in the house, never mind when working 9-5..... Working dogs in general is always going to be a challenge given your situation, Labradors to an extent are an exception here, good ole Labrador
If my advice is helpful at all please feel free to trust message me or ask away in here I can blether on a lot more than I just did. I have plenty of contacts and information/knowledge of breeders through the UK for several breed types and can help with anything you are stuck on.