Lighting recommendation for light tent

[mercurius]

I have a light tent which is a reasonable size that I would like to use for photographing still life (up to now I've tended to use it mainly with ambient light)

The lights I got off eBay have proved to be unstable and unreliable, and I would like to replace them. Any suggestions for types / makes to look at? Not a big budget for this - c£20.

Thanks for any suggestions.