Here's a review by one of our members of
a number of small dishes.
You might be surprised how they turned out.
(I'd suggest you compare 36" dishes, instead.)
LNB standard vs universal - unless you need universal, it won't matter much
As I recall, there's only one bird you are likely to be able to see, that can use universal.
However, for some switching schemes, stanard LNBs might work out better.
That's a long discussion, and I won't beat it to death in this post.
Single output vs two output LNBs?
With both outputs, you can hook to a switch, and run multiple receivers (more than two).
If that's not a big concern, then single output is fine.
Of course, if you are hooking up dorm rooms or an apartment building, or located outside CONUS, or want specific birds only visible from the far east coast, or seeking C-band, that might be a contributing factor.
I'll assume you are looking for the Ku band programming you can find here:
FTA list
Global CM
Two very nice lists of satellites and services, much easier to use than Lyngsat.com