Welcome
potluckman!
Self installs were done by those of us with our own dishes, LNBF and satellite meters. With that said, your DirecTV dish is not suitable as it is designed for multi-satellite reception and the multi-feed LNBFs are the wrong polarity (circular) and frequency range (12.2-12.75GHz). As a hobbyist, one might fabricate a LNBF holder to place a linear LNBF (LO 10750 Freq range 11.7-12.2GHz) at the correct sweetspot, but the dish would still perform as one with a smaller than acceptable diameter.
In your case, I would suggest that you are a perfect candidate for the OrbyTV install. By the time you source your own dish, linear FSS LNBF and attempt to install without a meter, you are better off getting the OrbyTV dish, LNBF, diplexer, OTA antenna and install for only a little more in cost.