I would imagine that the larger opening letting water out of the sock chamber will not matter in terms of sound because that space is unrestricted but fully submerged so it just creates flow speed based on your return speed. Usually, the sock chamber makes noise where there is too much height...
You can, once you've been a member long enough and contributed via other posts... Theres a pinned post on the very top of the Selling Forum section that outlines the rules. In case you need to see it, here's the link
I have some miscellaneous gear I'd be happy to give them, if they have use for it. I also have a tank/overflow/lid that I have posted for sale, but Id be willing to donate it to them, if they end up being able to use it for their program.