I have used opensourcedesign.co.uk they seem good, as they answer email real quick, and can be telephoned almost 24x7 i've tested this
You dont need to spend that much ..
How can you know without first knowing the requirements? :|
I know as i own everything![]()
We used a company called Vittol Ltd to do some work for us recently and they were fantastic (really cheap) but if you're looking for a top designer I would recommend a guy called Will Smith - www.authenticstyle.co.uk he's by far one of my favourite designers.