I've been building up a guard list over the last few weeks, and I've decided to go with vets as I really wanted to focus on having an army with BS4, having come from no-markerlight tau and khorne daemons.
What I propose is a second platoon in the troops section, very literally a platoon comprised entirely of veterans. You get points for drawing members of this platoon from different companies and regiments, of course.
What I've tried to do is simply scale the infantry platoon to the veteran's bonus options, without making them stupidly powerful or anything.
Given the nature of this platoon, I would make two suggestions first and foremost:
Veteran platoons are capped at 0-1.
An army that includes a veteran platoon cannot take normal veteran squads. (they're all in the platoon!) - this is useful, because it means your player HAS to take a normal platoon as his second option. Must take 1
PCS and 2 Vet squads
Veteran
PCS Take: 1
Obviously the Infantry Squad is copy-pasta of the vet-squad options, take 2-5.
Veterans can buy the Combined squad Special rule. for +5 points per squad.
Heavy Weapons Squad 0-5
SWS 0-3
Conscripts
So, Thoughts? This was just an idea at this stage - every value uses the 1.2 modifier that vets have over normal squads, and I've tried to get the combat doctrines per model price for each member of the squads.