Reflectors on the light clusters would be good enough for the MOT. Dual fogs has been done, but it blew the bloke's fuse and caused him other problems. Can't remember what exactly.
I also have two fogs, but one isnt wired up. If i was to do mine, i'd probably give it a new live & earth and change the original one to run off that, instead of through the fuse panel.
Anything new should have it's own system made up for it really, it just causes less problems in the long run.