Appreciate the help segara82.
Using that input, here's what I decided on:
If hurrying, this is the time it takes to don armor:
Imperial Guard Flak Armor: 5 minutes
This is a single suit of ballistic armor (tho boots & head-piece are separate) but involves multiple layers that strap and fasten around various parts of the body.
Boots: It includes boots, which has armor built-in, but they are separate from the suit. To just put on & lace up the boots it’ll take 60 seconds & afford 1 AP to the legs. (Which reflects same armor but much less coverage than the suit.)
Head-piece: Note that the “Flak Helmet” is 2 AP and this one with the IG suit is 4 AP. That’s because it is both better armor and better coverage. Unlike the Flak Helmet, it covers most of the face and it’s integrated with the suit, thereby affording better coverage to the throat region. It can be detached from the suit, but it can’t be just “put on” and “taken off” like a helmet. The head-piece can’t be donned without the suit, because it's made to fit into and attach to the body suit - which, unlike the Flak Helmet, is what affords the excellent coverage.
Attaching/Detaching the integrated head-piece from the suit takes 30 seconds if you’re not wearing the suit at the time – double that if you’re wearing the suit at the time.
Donning just the bottom half of IG Flak Armor suit can be done, but takes three minutes to don both pants and boots. Having the top half of the suit hanging there (head-piece cannot be attached while it's hanging there) reduces character’s agility by 5.
Enforcer Light Carapace: 7 minutes
It’s a suit with integrated head-piece. Due to the interlocking nature of the various pieces, the whole thing must be worn or none of it. Head-piece attaching/detaching times are the same for IG Flak Armor above.
Armoured Bodyglove: 2 minutes
It's a one-piece (not including head-sock) very-skin-tight glove but this armored version is notably thicker than the simple "neoprene" version. That makes it a bit hard to work with - think of a wet wetsuit - which is where most of the time goes in donning it (and 2 minutes is actually pretty quick). Head-sock is a separate piece & completely covers the face save for eyeholes.
Head-sock - Part of the head-sock is tucked underneath the body portion of the glove. If one is just wearing the bodysuit, but then wants to put on the head-sock - that takes 20 seconds to don.
All Flak Cloaks: 1.5 minutes
This is more than a “coat”, or else the lower portion of it would flap around significantly during combat operations. There are a series of straps on the legs that make it fit like more like secured pants – but appearance-wise, it looks like a cloak…and hence the name.
Flak Vest: 30 seconds
Heavy Leathers: 1 minute
There really aren't any straps to mess with &, as a result, it doesn't really stay in place during combat operations very well...which contributes to the low AP.
Light Power Armor: 20 minutes; 15 minutes with help.