Bob,

Unless the antenna is up in the clear, the full gain, F/B, and F/S will not be
realized. You might be better off using 1/4 wavelength per side, rather than
3/4, and get the extra height instead. As to feeding it, open wire line will
work quite well, over a broad frequency range, and be virtually lossless at
even high SWRs negating the need for a balun and the associated problems. Just
one ham's opinion.

73s,

Evan