I'd be concerned about the Gouramis - they aren't too friendly normally, especially to their own kind.
The Bala Sharks might be fine full-sized in that tank but I'd be careful not to let them get to be too big. Just make sure you have an alternative home for them within the year as a backup.
The swordtails usually like to be in a group and if you get 2 females to accompany the male, you might just (more like, you WILL) see some babies!
I'd get a bare minimum of 3 of each of those Rainbows as they would probably get lonely.
http://www.thetropicaltank.co.uk/Fishindx/rainbows.htm
Is this your first tank?