iMessage for Snow Leopard (10.6.8)

I am on a MacBook Pro, 2.4 GHz Intel Core Duo, with 4GB 667MHz DDR2 SDRAM, running OS 10.6.8.

I am currently deployed to Afghanistan (p.s. the internet is pretty slow over here).

I always have my iPhone with me for taking pictures, and there are a few hotspots near the USO area where I can access the wifi and use iMessage with friends and family back in the world, email, Facebook, etc..

When I am in my room, I do have wired internet that I pay for through an ISP called sniperhill. I use my MacBook Pro here in my room.

Is there a version of iMessage that I can install on my MacBook Pro to replace iChat and then be able to iMessage my friends and family on their iOS devices (the folks I am messaging all have iPhone 4S or newer). I found a place to download iMessage for Mac, but after a 45+ minute download, it turned out to require 10.7 or later. D'oh!

I use iChat sometimes to video chat with my wife and kids, but they aren't always on the MacBook at the house. If I could iMessage them while in my room on my laptop, then we could coordinate to have them power up and hop in front of the MacBook at home, then I could use FaceTime 1.0.2 to chat with them.

Any suggestions?

Thanks!