Are you looking for combat uniform, or more formal duties? The technicalities on precise uniforms can get a bit intimidating, and there was one fairly big change in the middle of your period.

Early: Conscription, still essentially WW2 battledress, webbing, and weapons

Late: Volunteer army, combat jacket, '58 pattern webbing, British versions of the FN FAL rifle and FN MAG machine gun.

The changes happened over several years, as the attached photo shows.

If you have a clothing conversion utility, to use the P5 Female Combat Jacket (they did the combat pants, but not the jacket, for the man--crazy!), you can at least get something of the right look for the sixties.

The Parachute Regiment wore the Denison smock all through the period.

PoserWorld is good.

Useful for some uniforms, etc.

Vanishing Point has the various weapon packs designed by Panko.