I am primarily interested in having clubs, forums, and pages.  If I choose to buy self hosted, do I need to purchase "gallery" and "downloads" in order to have the club features called "files" and "images"?  Or are those club features still included if I don't purchase "gallery" and "downloads"?

Thanks

The club features will only appears if you have the related application installed in your Community. 

You are indeed correct in the 2 applications you would need to purchase in order to have those 2 items. 

9 minutes ago, Marc Stridgen said:

You are indeed correct in the 2 applications you would need to purchase in order to have those 2 items. 

Will the option in this image ("drag files here to attach, or choose files") still be available to members when posting in forums and clubs if i don't purchase "gallery" and "downloads"?

 

Yes, that is the attachment option.