Help on Instalation of new antenna

my dish is on top of a 40 foot tower that i installed 15 years ago. I live in a valley between 2 mountains in charleston WV 101 sat is fine. I cant get the 110 & 119 because of the mountain & trees I would like to change my dish to pick up the HD channel on 99 &103 since they are at a higher elev. I would like to know what new antenna I would need to get & since I cant see 110 or 119 what is the best way to adjust a new dish. I Will Have to install the new dish since it is 40 feet in the air. any comments would be helpful for a newbe in the group. Thanks