http://www.mediafire.com/  
 https://www.dropbox.com/ both for storage/download/upload possibilities.  
http://lifehacker.com/5503770/five-best-online-file-sharing-services  - check it out for the top file hosting sites.
  
 http://audacity.sourceforge.net/ 
 http://www.nch.com.au/wavepad/ the two programs I can use to record multiple tracks. 
 
have 3 people, pushing it at 4, no more than 4.  keep them in the US, try to get people with a relatively level head. rockband mic most likely...that worked well over skype and gmail chat.