I'm not sure whether you can get it done with a matt finish - it's probably worth asking. Or do you mean you want it glossy? It is pretty shiny, but you can get metallic or "candy" colours which are shinier still, though they do cost more.
It was done by
Triple S in Bradford. From what I gather, they are very well experienced (they mainly do motorbike and classic car parts but they do bikes as well) and have been doing this for decades, so they know what they're doing. They know how to handle bike frames in terms of masking the threads and plugging holes and so on, which is where a lot of cheaper outfits fall down - you'll not thank someone for doing the job cheap when it turns out you need to get your bottom bracket threads re-cut.
The cost was £102 including VAT and return carriage. On top of that I'd paid £12 or so to ship it there in the first place. It's probably way more than the frame is even worth, but I wanted it doing and I had the money. The cost depends on whether you get the frame and fork done (I only had the frame done) and the colour and so on. Some people will say that £100 is a lot for powdercoating, and that you could get it done by some bloke in a shed for £50, but I really think it's one of those things where you get what you pay for. Maybe I could have had it done badly twice for the same money, but what good is that? I've read stories of people getting frames back from cheap outfits with very uneven covering, lumps and flecks in the surface, ruined threads, etc.
In terms of timing, a courier took it from me on the Tuesday and it was back with me the following Friday, so it was away about 10 days all told. Probably in their hands for under a week, once you factor in the courier time.
I can totally see myself using them again to do my single speed bike in a few years once that gets dinged or I fancy a change of colour, or if I end up buying any old bikes in the future, which is pretty likely to be honest