Frankee
If you are looking at some sort of payment plan take a good look at the small print. Some of these deals look good but are spread over several years and have a high APR. Look at the total amount payable.
Secondly check out the Buy now Pay later options. Some of these sign you up to a credit agreement that if you don't pay off the sum on the date indicated lock you into a long term repayment scheme that cost an arm and a leg.
If you are in regular employment, maybe a bank loan ( you wont get a really good rate for amounts under £1,000,) which in the long term may be a better option. YES banks are lending to people, provided they are deemed a reasonable risk.
May I suggets you find the laptop you like then shop for the best deal