I hate mixing powder, but if I shoot smaller than 4x5 I still use D-76/ID-11. Its cheap and readily available. I tossed the stop bath a long time ago. I just use water. Some people say you need it, others don't. I have found I don't and its one less chem. to keep in stock. I prefer rapid fixer (ilford or arista)...I get a bit impatient inverting my tank for more that 5 or 6 minutes.
I would suggest that you consider using Rodinal as a film developer, it is relatively cheap, it's an excellent developer and it's liquid and it lasts forever. As you are at the beginning of your photographic journey you are not likely to be shooting huge amounts of film and other developers do go off if stored for too long. Use plain ordinary water as a stop bath for both film and prints, I've done so for years and have experienced no problems whatsoever. Ilford or Fotospeed fixer is OK. You may want to call Fotospeed at 01249 714555 and ask for their price list they do some good chemistry that I use regularly. Silverprint are also worth looking at although they can be expensive for some products.
Don't purchase anything from Jessops, they tell you they are the cheapest but the Jessops brand stuff they sell is junk, so it's not that cheap in the long run. I know this because I've visited their warehouse in Leicester and talked to the purchasing director about their policy and I've seen the specs for their chemistry and they use the minimum raw chemicals possible.