Hi Tony
I would say going second hand will get you something more than good enough to work out if 5 strings is for you or not and I would recommend something from the for sale section of this forum where I have had some cracking basses including my first fiver (and many others). If you can get something local to you then try it out first. Certainly try some different string spacings and neck profiles, with five strings to stretch across you may want to go for a slimmer neck profile than what you are currently used to on a four but this is not necessarily so, it will depend on how you want to play on the fiver.
As for brands well it is hard to touch the Ibanez offerings for bang for your buck, but I would say that Yamaha are certainly worth looking at as well.
Good luck