use a remote line powered preamp near the antenna. Put it in the attic
if you want to be able to serivce it. You can use RG6 or even low
loss RG59 is you use a preamp near the antenna.

since yo uneed it for UHF only, try to find one that has only a little
gain at VHF.

The key to a good signal to noise is to have a minimum loss BEFORE the
fist amplifier. Putting the amplifier after the coax is NOT as good as
putting the amplifer before the coax.

But a few feet won't hurt so mounting it in the attic where you can get
to it easilly is a good compromise.

Mark