Hi there

why dont you try this website

http://www.ownersdirect.co.uk
http://www.holidaylettings.co.uk

it might end in .com rather than .co.uk

i have alwasy for the past 7 years rented from http://www.ownersdirect.co.uk adn alwasy been brilliant

other than that try Alpha rooms.co.uk

It might be chearper to get a 1 bedroomed apartment and the frontroom then converts into a bedroom well sofa beds

thats what we haev done in the past and they haev been roomy enough as well, loads of storage and we tend to stay for 3- 4 weeks and its 4 of us 2 kids and 2 adults

Good luck hun