We have one and no problems at all with the quality. We had Broadoak and painted it ourselves, my mum has Clayton and they both look great. Clayton might be a good choice for you. Broadoak you can faintly see the grain, Clayton is very smooth.
Couple of things:
The carcase units are as good as you will find anywhere for a chipboard kitchen, plus they have huge choice of sizes, extras, finishes etc. Really no need to worry on that front.
They do a big range of doors at different price points and so the cheaper ones will be foil wrapped, the more expensive lacquered or painted wood . I would really recommend getting sample doors if you are trying to choose between a few. Or ring them and ask them to explain the different finishes.
For the F&B colours I suspect they use a hardwearing spray paint tinted to colours licensed from F&B, but again if you get a sample it will soon become obvious. F&B themselves do a range of different paints with different finishes (matt, eggshell etc) , it is not one paint.
The DIY bit is doing your own measuring, design and parts list so if you are not confident in that then perhaps read up on it or enlist some help. But in the end you can do it on graph paper and they have lots of information on their website on how to handle corners etc.