(Apologies for the copy & paste from another thread)
Disclaimer: I work for an independent regional kitchen retailer in the North East and have been in the industry for 20+ years.
Wren is universally considered to be the worst "big" company to purchase from. Their product is substandard and overpriced (in comparison to competitors) and their customer service is dire.
They have gorgeous showrooms and are very good at bedazzling potential customers then pressuring them into signing away a deposit.
Wickes is by far the better company, both in quality and in service, however like most "Supply & Fit on finance" companies, they're wildly overpriced for the product they offer.
DIY Kitchens offer a semi-decent product at a decent price, but be sure to look into the small print:
£75 delivery charge for delivery on a 2 day window and you have to offload the kitchen yourself.
£150 delivery charge for a 2-man ground-floor delivery on a 2 day window.
£250 delivery charge for a 2-man ground-floor delivery if you want to choose your date.
No cancellation once the order is in production.
No returns on cabinets/painted doors/accessories,
25% restocking charge on "allowable" returns after 10 days,
You pay carriage + have liability for transit damage,
No paint matching after 1 month.
Their painting methods are susceptible to whisper lines and cracking along the joints per their own terms and conditions, and they charge for "touch up pots".
Be sure that you're ordering exactly what you need (and nothing that you don't) and have factored the additional costs of delivery / touch up pots (you can only get them in an identical colour as your doors/etc within 1 month after which they dispose of your paint batch)
Smart money says go to an independent in your local area and find a reputable fitter. If you don't have the cash to pay for the project without finance; take out a low interest bank loan.
The savings on the kitchen price will more than offset the interest that you'll be charged on a bank loan over 5 years.