Hope this pic attaches. Cap badge of the Princess of Wales Royal Regiment (Queen's and Royal Hampshires), as with UK_SKA_RULES above, the main reason for this is their the locals. I think you are letting yourselfs in for a major poll as to which ones to do. Everyone in the UK and possibly outside the UK that plays this game is going to want there locals or favourite.
As a thought, and not being a addon guru I don't know how difficult this would be, possibly a big job? I counted 35 on the badge page link and that was only infantry, some of which you are doing, but how about doing one unarmed model of each, mission makers have the info they need to add weapons as they see fit. If you where only to do 6 badge types and have 5 types of troop under each ie officer, rifleman etc it would still be 30 models, about the same amount ?.