Palm Treo 700w / 700wx

my friend said that this phone can have AIM on it. Like the AIM version u can get on windows not the get it now version. How do you get that on your phone. Do your download it onto a miniSD card from ur comp and put it on or can you download it right from the internet expolorer on the phone?? also when you use the aim does it count as texts or is it free?? whts the deal please helpppp