Dan,
We normally try to be weighted neutral at a depth of about 33'- not floating and not sinking. If I am diving shallower than that, say 20', then I will weight myself to be neutral at half that depth- say 10'.
If you noticed my belt last week I have a bunch of small weights, all around 2 pounds each, and I take them on and off all the time as I move into different depths throughout the day- they get tied off to the float. This is done for safety's sake as well as ease on my lower back. Nick has those really nice weights, only 1 pound each, that I would love to have- maybe for my birthday.
Insead of shelling out over $100 for a vest I would spend a
lot less and invest in some, much, smaller weights than what your using now. If you get a decent rubber belt, like this
Marsellaise belt IMERSION Belts Accessories United States Of America Dive Scuba store .com , you'll be able to switch weights around with, relative, ease. Since you have a dive kayak you can just toss them in there when they are not on your belt.
Jon