Have a look at YouTube videos by "kitchinsider" and "Nick Morris" (who also posts under "1936 Bungalow Renovation"
I've picked up lots of information from their videos, and I've ruled out lots of things based on them.
In particular, the Nick Morris one where he compares kitchens on a like-for-like basis from 5 big manufacturers - Wickes, Wren, Howdens, Magnet and DIY-Kitchens. DIY-Kitchens came out on top on most things.
We had a quote from a local kitchen supplier, which was £33,000, plus appliances. It was beautiful, but I just can't justify paying that.
So my husband has gone onto DIY-Kitchens website, and replicated the design, and it comes in at £12,000 plus appliances. (It is a huge kitchen.)
The only downside to DIY-Kitchens is that they don't offer a design service, nor do they offer a bespoke service, so there is a small gap on one wall, whereas the local company could make cabinets to fit perfectly.