Is BG 2 EE out? And several other newbie questions

Hello. New here. I found out that there was an enhanced version of BG a few days ago.

I see the BG EE version came out several mothns ago, and a BG 2 EE is being worked at. Is it known when it will be available? Which oeprating systems will it be for?

Regarding other questions, where can I buy BG EE apart from Steam? Is there any problems with the Windows version I should be aware of? Anything else of interest?

Thank you very much