Carol,
Don't be disappointed,
You installer has no idea what he's talking about.
IF he can get signals from the 99* to the 119* you can get the Standard channels, provided he can get those sats in, you will also be able to get your HD as well.
IF he says he can get the SD channels, the main core programming is on the 101* sat he should be able to get the 99* as well.
I would call and get someone else out there and try again.
NO reason that you would get only SD if you can get the 99-119 range of sats ..... The 99* is barely used at this point, so as it stands right now, the the HD is mainly on the 103*, and he told you he could get the SD so the 103* is inside of the SD arc ...
Have them try again
Jimbo