I get most of my cables from monoprice.com. I can get a 100’ RG6 cable with F connectors on the ends from monoprice cheaper than I can get 100’ of bulk coax locally.
Do you have a small TV you could move near the access to your attic? Then you could put the antenna in the attic, run a long cable to the TV in the house, and see if WPMT comes in. No sense in drilling holes until you find if there is even signal up there.
Do you need ABC from VHF 10 or the programming from W07DP-D from VHF 7?
If you really only need CBS, CW, PBS, NBC, and Fox, I can see why you don’t want to put up an outside antenna, you are almost there with an indoor antenna.
I suggest you go to
http://www.rabbitears.info/search.php, put in your zip, address, check signal strength, and see what rabbitears estimates your signal strength for WPMT is. If there is a big difference between estimates, the signal strength from WPMT may be less at your house than TVfool is predicting.