Also, I would think that, from Longview, you would need to get an antenna really high to bring in those Tyler stations.
Not at all. 20-30 feet should suffice unless you are on the northeast side of a hill. 7, 51, 54, and 56 are easy. 19 is a little more difficult but should no problem with a decent outdoor antenna and preamp. I get all of the Tyler stations, including 7, with a CM4228 8-bay (old style not newer 4228-HD) pointed at Shreveport at about 25 feet.
"The only reason you are still conscious is that I don't want to carry you." - Jack Bauer