You will need to rewire your lights, On my old import I think one of the lights doubles as the fog, I'm not sure how mine was done, it was like that when I got it, as far the Indicators go, you can get amber leds, which should suffice for the MOT and Mr Plod.
Try
www.ultraleds.co.uk you will need the resistor also, otherwise you will have rapid blinking.
As for the lenses themselves, they are not as robust or weatherproof as the OEM ones, they are unsealed and will let in condesation.
Clear silcone wll sort this, but it can be messy to apply and if you are worried about a perfect fnish, I shouldn't attempt this
They scratch easily also.
If you want them they're not cheap, and are really only suitable for the Summer, in whch case you'll need a set of non uk oem rears for the winter.