Robert I own the thf6a and the second receiver has more coverage than the k2at.  Determining what goes into a go kit is very much a matter of choice for each individual and the length of time you're going to be in the field.  I have 2 battery packs for the thf6a plus a home brew one I made up a number of years ago when I helped provide communications for the Marine Corps Marathon. 73- pat kk3f