OME are probably the best readily avalible, after market, springs and dampers in the UK. However I've been using various combinations of Britpart, Bearmach, Procomp, Rough Country and OE springs + dampers and they have done me well for the money. Britpart springs are the only ones I wouldn't buy again.
It doesn't matter which brands you go for, to get thew best out of them the springs and dampers specifications should be suited to your requirements. What are your requirements other than to raise the ride height 2 inches?
What do you do with the vehicle and how much do you do it, do you want much more suspension travel or about the same, has the vehicle got much extra weight added (HD bumpers etc.), are you trying to creaste space for bigger tyres, what is your budget?