I think that should work. Someone with more experience can chime in and correct me if I'm wrong. The 9.75" is the height? I heard you don't need a very deep tub. Mine is only about 6" deep and it seems to do fine.
I suppose the overall length and width would depend on your snake size. A small to medium sized snake should be good in the tub you mentioned. (Again, correct me I'm wrong).
Make sure you have clips or something to secure the lid. In the stickies of the husbandry section you have vypyrz tutorial on how to make that tub set up. I used it, and it is magnificent. I believe he gives you facts on tub size too! Good luck!
Tapatalk with the Inspire 4G