Just to add my own $.02…
I am in Arizona, USA and can receive G19 just fine with an inexpensive 76 cm dish. But possibly more noteworthy is that I can also receive it reliably with a repurposed DirecTV “Slimline” dish. This is the largest of the DSS dishes, but still small at only 22 inches high by 32 inches wide. While it requires careful aiming, fine “tuning” is facilitated by screw adjustments for both azimuth and elevation. I removed the original monoblock and added a generic mounting bracket and LNB.
EDIT: I should add something I see nobody else has mentioned about repurposing a Dish/DirecTV dish and that is the fact that the original LNB on those dishes is NOT compatible with Outernet (or, for that matter, FTA TV either) because the DirecTV and Dish Network satellites use circular polarization (L/R) while Outernet and FTA use linear polarization (V/H). So if you want to try to use a discarded Dish/DirecTV dish, you’ll need to change the LNB as I did on mine and you can see on the photos.
With this arrangement, I’m able to get 90% signal and 55-65% quality (depending on transponeder) on my TV receiver, and 80% signal, 86% quality, and 90K bitrate on Outernet Lighthouse.
Note the use of a dual LNB - the Lighthouse is connected to one output, and my TV receiver to the other.
Discarded dishes are easy enough to find for free, the bracket was about $6 and a suitable LNB costs between $10 and $20.
So, while I’d recommend a 76cm or larger dish if you can afford it, if you’re on a tight budget, handy, and don’t mind your system being a bit more prone to rain fade, go ahead and experiment a bit, knowing that while it may not be recommended nor officially condoned, it HAS been successfully done.