I didnt say glass doesnt scratch, I just said acrylic scratches WAAAAAAY easier.
Ive had 3 acrylic tanks and being extra careful they still looked like someone went at it with a brillo pad, I even repaired one of them and it made the acrylic all wavy. My starphire tank has one scratch in it after 3 years.
Either way if your putting it on a steel stand glass would work better but a 3/4" sheet of plywood would make it work fine for acrylic if you decide to go that route.
Not going to turn it into an argument, its OP's choice just saying for under 100g tank there really isnt any noticeable advantage to acrylic.
And either way OP, for a tank that size....why not just make it yourself? its not hard, and not expensive either.