That looks like a good selection. walMart has some in the automotive dept, believe it or not. I've used them, though on an occasional basis.
Depending on how much sun you'll get a full season outdoors will pretty much cook the cheaper ones, but they are lightweight. So you'll be buying one each season or so. Better than faded tank and burned up seat.
The half size are good for your purpose, don't have to let the pipes cool before installing.
