The bag is 10 x 16 x 70. Here's a link where someone is getting rid of that size.

https://forum.supraboats.com/showthread.php?t=8303

Bulging isn't a big issue as long as you watch it. Overfilling the bag can cause some bulging that would push up the cushions a bit.

If that link doesn't work out for you post a wanted ad here and on the Moomba forums. Like I said, that is a standard bag Skier's Choice uses in Moombas and Supras and people commonly look to upgrade to bigger ones and sell their original.