Go to the winegard web site and look at their dishes. They sell a good variety of different sized dishes for dish network that have the D-tube lnb arm to fit a single DP lnb, so you want need any kind of I adapter. I think they go up to about 36" with the d -tube arm. That should be plenty big enough to get a decent signal.
Yes, I have looked at several sizes at different web sites.
But the three dishes I listed above I already have. I don't what to buy another if I don't have too.
I would use the Dish 500 with a "I" adapter then. There have been a few people on here that have mentioned that they get a better signal on 129 with a dedicated dish500 with the adapter than they did with the Dish1000. There isn't anyway that it couldn't get a better signal. The dish size is round which is perfect for single sat use and the lnb is at the highest gain point of the dish unlike the dish1000 which is 10 degrees out of the main focus of the dish. I would expect a 7-12 gain in signal strength and alot better performance in rainy conditions.