Ikea kitchens have 2 different kind of drawers. The more expensive drawers are much easier to put together. The cheaper ones are such a pain. I almost gave up at the drawers also. A year later my mum opted for the soft close upgraded drawers and what a revelation putting them together was and the extra cost was not even that much more.
In this house I will be fitting another ikea kitchen, the quality to price ratio cannot be beaten.
Diy and units online is the best for quality at a very good price but they can't beat Ikea prices except on their most basic kitchens. Benchmark are good and they supply Wickes.
I don't like Howden because of their lack of transparency on pricing and convoluted ordering system. Magnet, Jewson, b & q, you can get much better at better prices. The rest of the high street are very much the same quality at inflated prices.
With Wren I think you need to be lucky to bother with them as they have quite extensive and known problems with their service, fitting and delivery. People who have a decent time with Wren just got lucky.
11k for a wren kitchen is a rip off when you can find far better quality elsewhere for cheaper, Wickes, Ikea, Diy and are all better for a much better price.
Independents can be very good. German kitchens are very good and handmade is great. If you want a cheaper handmade option then Pineland kitchens are great. Devol and their ilk are good.
Op don't succumb to a fancy showroom, go for the best units you can afford, matt is better than gloss and go for doors that can be easily repainted.
Diy kitchens and Units online are a great starting point for quality and price. The kitchens at higher price points like Tom Howley and The Shaker Kitchen company (which has changed it name) have suffered from some problems, so price is not an indicator that you are getting a better product and/or that the service will be top notch.
Even granite can be bought and fitted cheaply so don't assume it will cost 3 -5k, there is granite around that costs the same as laminate to buy and fit. Wood is very cheap from Ikea.
Tiles are available at all price points and online is generally far cheaper for often the same products. Same with lighting, look around and wait for discounts.
Get a interest free credit card or save up for everything. Don't go for the shops finance unless interest free like ikea and make sure its long enough to have paid it off before it reverts to their super high interest rates.
Op there are a couple of threads on here, the kitchen lessons learned one, there's a show me your kitchen one and also the how to replicate Devol kitchens which was useful. Good luck.