Hi Dave,
Awesome GTI are probably the closest 'popular' specialist. There's also Votex in Congleton, although I've never used them myself.
ABP Motorsport in Shavington are good for garage services, and have won a lot of awards for being a trusted garage. They are very familiar with the mk5 platform & keep OEM VW oil in stock. They have done lots of work on my MK5s over the years, and are particularly good at alignment.