1. Which stores are recommended for suites and tiles? I have found as few Armitage Shanks and Ideal Standard models at good prices and baths all seem much of a muchness. For tiles, Wickes have the exact tile I am after (Everest stone) at £12.49 (1/2 price). Any issues with quality?
Armitage Shanks and Ideal Standard are fine as far as quality goes, I would have no problem fitting them, I am sure other fitters would feel the same. Regarding tiles, make sure they are a suitable quality, its not easy to tell but I have had some from the likes of Wickes/B&Q etc.... that are poor quality. Examples of this are tiles that are slightly warped, i.e. not flat, an absolute pig to fit. You can also get tiles that are very slightly different sizes and shapes, only by a mm, but this makes a massive difference when trying to put them on the wall. Other issues are digitally printed tiles, I have had a batch of these and the print is slightly off centre so the tile looks wonky. Finally, some are very soft, lovely to cut, but can be fragile. Grade 1 the softest, grade 5 the hardest. For some grades you need diamond drill bits to make even the smallest of holes. In general, its worth remembering, you get what you pay for.
2. Would the plumber/fitter generally prefer to have a hand in picking the suite and in the design rather than being provided with a fait accompli for him to install?
Personally, I don't mind what you buy, other than the really cheap nasty cheap stuff, which can be a pig to fit and may never be right. It would be foolish not to involve your fitter in the design stage, some things are either possible, not advised or impossible. I have been to many jobs and half the design has changed due to soil pipe locations, integrity of walls (wall hung items), joists etc.... I went to a quote once and the customer had pre purchased everything prior to getting quotes and in my opinion, not one thing was suitable, i walked away advising of this
3. To Sam in particular, is being booked up until June a case of having no availability or, if a project was trimmed in terms of the time you would need to spend (it being a day possibly just to do pipes and install suite), do you have earlier availability?
Every job is different, there is no such thing as a simple swap. I have never had a straight swap. I am sure its possible, but I never find it to be the case. A day is not enough to fit everything. Some people will and can do this, not me though. I have had the displeasure of seeing some absolute shockers by people who, rush, underquote or are just under skilled. There are so many variables, it would be impossible to list. One example though is tiling. I like to tile behind basins and toilets and put the flooring under as well, this cannot be done well after the plumber has been in to fit all the suit.
My advice, whether I do it or not (i'm not short of work as you know ) is wait for the right fitter, who you trust. Its one of the main rooms in your house and can potentially cost a lot of money, you are risking this investment if you rush the project. I probably turn down 3 bathroom jobs a week as people are not willing to wait, even people that have had me personally recommended by a friend. Most of the tradesmen I know and respect are booked up for months in advance, as they should be. Be patient and get it done right. I am more than happy to offer free advice over the phone or internet. Good luck with whatever you decide.