what tool you are using is going to be the first consideration. are you using an airbrush or a mini spray gun ?
the noise level of the compressor will be your next deciding factor.
If its going to be in the house somewhere and you have other people living with you then you obviously want it as quiet as possible. If its going outside in a shed then noise isn't a consideration then your options are a lot more.
I have a compressor very similar to the 8 Gallon one you linked. 79db is what its advertised at (the one you linked was 81db so they'd be almost identical. mine is in the house, can I hear it - yes, does it want to shatter my eardrums ?, no.
the size of tank only means that it will refill less often.
you mentioned spraying canvases. are they smallish 3 ' x 4' ones ? Do you only work on one canvas at a time ?
From what I've read on your previous threads the 1 Gall will do what you want it to do.
Don't forget to drain the tank weekly if its getting a reasonable amount of use.
If you are physically able to go to the store to collect then take your airbrush hose with you and ask for the adapters to suit