Whether you need/want all-season tyres will really depend on how capable you find your current tyres. All-season tyres are more expensive, so depends on whether you'd be getting the best value from them. For example, if you live on a hill or down a steep driveway, regularly see snow and/or ice where you live, or simply find summer tyres don't give you the grip you want in winter months etc - then I'd advise all-season tyres. If you see regular bad weather that affects your driving, I'd probably suggest swapping between summer and winter instead — i.e. northern parts of England and Scotland could require winter tyres more so than all-season as the weather can get more severe than, say, in the Midlands.

If you want all-season tyres then I'd recommend Michelin CrossClimate+ or Goodyear Vector 4Seasons Gen-2. As for 'standard' summer tyres, I'd probably go with the Goodyear EfficientGrip Performance 2 as they're quiet (A for wet grip, B for fuel economy, fairly quiet) and refined. Another choice would be Michelin Primacy 4 (A for wet grip, fairly quiet but only a C for fuel economy). Bridgestone Turanza are rated A for fuel economy and wet grip, however, they're rated at 71dB for noise, which can be considerably louder than tyres under 70dB.

I'd check Kwik Fit and Black Circles for deals, Black Circles certainly has some for the ones I've mentioned. ASDA tyres might also be worth a look for offers and discounts. It's best to shop around online as the deals change regularly but there are usually offers to be had if you're buying a full set.