The glass build plate I use is 9"x6" 1/4" thick. I use a couple of these at two corners to hold the glass https://www.thingiverse.com/thing:613685
I've printed with Hatchbox and ESun. Both PLA and PETG from Amazon can't beat free 2 day shipping.
I prefer PETG over ABS it's a high heat Filament. I print it at 230c and 70c bed.