Newcastle
I have always found the GA handling company at NCL to be extremely helpful and friendly... however not cheap. They are based on the south side, but will run you round to the main terminal for the metro/hire cars etc. Also being across the runway from the big stuff means that you don't get involved in all that security business.
Give them a ring for charges Tel: Operations: +44 (0) 191 2864156
or their website
http://www.samsonaviationuk.com/index.html
Despite all of the pictures of jets on their website, they do do PA28s too.