I'm thinking of comming back to dish- would need the 1000. If you had a choice between a chimney mount and a roof mount, which would you choose? Pole mount is not an option. Snow is not an issue- Raleigh, North Carolina.
You should have a good LOS to 61.5. You'll be much happier than dealing with 129. So much so, you should ensure the installer knows you will not accept anything less, and check the guy before he starts work to ensure that he has in fact brought both dishes. You'll get all the Voom channels, plus the HD demo channel, on 61.5.
chimney mounts are bad news, chimneys were designed for venting not as a structural mount for a wing.... which a dish becomes in windy conditions. feel one in wind they actually vibrate.
Speaking as one who nearly died from carbon monoxide after my chimney cap cracked and rain froze dropping the liner in the flue and blocking it...
vibrating dish weakens chimneys.
if you have a chimney mount have someone knowledgable check it completely every year from close up and above too, looking down inside.