i know mate !! its a mine feild isnt it........
i will tell you what i was told from tony from dutch passion ......He said there are two reputable UK companies that sell LED's that work and are tested ...... the two companies are LEDhydrophonics and Grow northern.
I nearly went with grow northern but then i saw the LEDhydro lights and i ended up buying a helios pro 6 as it is new technology as is their photon range i believe....
After much research i bought the helios and im glad i did, it costs more though, but if you email LEDhydrophonics they will give you a nice quote i think as it says on the web site.
if i was you and i didn't have the money for a helios ,personally i would go for a photon LED
im not saying grow northern lights don't work because they do , the reason i went with LEDhydrophonics in the end is because there technology is newer (and tested) and they offer a 5 years warranty and 90 days money back guarantee
...... its make ya mind up time haha