Larry,
I don't think a balun would do any good in your situation,
but it wouldn't hurt to try one, I guess.
There are other 'tricks' to lowering the SWR besides using
a balun. Seperating the various 'legs' of the antenna more,
changing the angle between the 'legs', and so on. Depending
on how you have the antenna mounted, changing it's 'shape' is
quicker/easier/cheaper than adding a balun, so I'd try that
first.
If you do try a balun, a 'current' balun is almost always the
prefered type to use. As long as it's rated for the power you
plan
to use, just make it 'cheap' for your self. And, since coax is
cheaper than buying a balun, I'd give the coaxial 'choke' a try
first.
I doubt if it helps with the SWR problem, though. Can't hurt to
try it, so why not?
'Doc