I'd be looking at a directional VHF antenna for channels 8 and 10 coupled to a broad beamed UHF antenna aimed at about 165, favoring the US stations but also able to receive Mexico.
Directional VHF antennas are rare these days, but here are two choices:
http://www.mcmelectronics.com/produc...-2475-/30-2475
http://www.abilityhdtv.com/product-i...nna-pid66.html
Your UHF antenna could be a C2, DB-4e, or any other 4 bay UHF antenna.
At your location you have no problems with FM overloading a preamp, so install a TVPRAMP-1R with the FM trap on and the VHF antenna connected to the VHF port and the UHF antenna connected to the UHF port.