If you're handy at all (and have access to tools) you can get kits on eBay, metal parts included you get your own wood. The kits come with instructions. I bought a kit for $75ish and my boyfriend built me my press. It's larger than most I've seen for sale and after wood and all I think we came...
Let me know if the campden tablets work out for you, I had a couple 1 gallon jugs I was fermenting and letting then sit awhile. I just noticed similar floaties, a bit smaller. I always wondered about headspace but can't say I've ever seen it brought up or mentioned as a concern before in my...