Okay Helen,try these links.They are all nice people and if you email them your requirements they will reply.
I don`t know which part of the country you are in,but Thwaites(Watford i think) are a nice old fashioned shop with rental option and a good selection of basses,Turners(Nottingham) has a great selection of basses from £hundreds to many £thousands,not sure about rental though,you need to ask.
If you haven`t alresdy done so,take Ed`s advise and visit Bob Gollihurs website,it will take days to trawl your way through all the links,but is well worth the visit(Bob is also a great guy to deal with if you need to buy anything from him)
www.thwaites.com www.soundpost.co.uk www.turnerviolins.co.uk www.ayresviolins.co.uk www.bristol-violin-shop.co.uk
One last tip........get Google as a search engine!
