If you're in Cleethorpes, you could pop into the Lincs Amiga Group's next meeting, Saturday June 2nd,
See:
http://lincsamiga.org.uk/I'd say the best upgrade for your system would either be a Flickerfixer so you can use LCD Monitors, or a Turbo Board with local memory, like a Cyberstorm or a Warpengine - We have one user who has an Apollo which is also a nice card :-)
Robert