Can you recommend any solar powered lights?

I've been searching the net for some lighting for our market stall. We will be travelling around most of the summer festivals selling Hoops and Hats. and I want to try and light the stall at night with solar powered lights. Now the problem I'm having is finding a lighting system that will work even on dull overcast days. I've found countless people selling the little garden lanterns, but I don't think they throw out much light and most of the reviews I've found of them say they do not work at all on over cast days.

Hopefully the summer will be bright and sunny, but in the UK you can't guarantee that it will. I don't really need these lights to be like flood lights as we hope to have a more soft ambient glow in the night than look like a night match on a football field, but I do need them to work all the time, whether the day has been 12 hours of bright sunshine or dull and over cast all day.

I saw these LED solar lights and though they would look great along the front edge of the stall, but again the reviews were nothing less than bad, saying they were not very bright and that they only lit up after a very sunny days worth of charging.

I really don't want to have to get a generator to run lights, as they are noisy, polluting and costly to run... any ideas all you lovely Blog readers? Have you go a set of solar powered lights you can recommend? If we can't find anything we will have to resort to tea light candles in jars, where the festival organisers will allow us, although that can be a fire hazard when slightly drunk festival goers try to hoop for the first time, late at night next to a candle lit stall.