I am visiting both El Chalten and Torres del Pain (entire circuit) this January for 3 weeks. All of my hiking will be without guides(except 1), just a lot of research to get to that point, can be done by yourself and if you have the experience and gear for the the weather down there. Want to do ice treks, I suggest a guide, want to wander around then by all means just go. I recommend Lonely plant forum for more information on the Torres del Paine area. The only guided hike I am doing is an ice trek(no experience or gear).
I suggest the guide book Trekking in the Patagonia Andes as it not only describes all the areas mentioned above but includes some alternative places as well. For a shop to go in BA go to the Camping Center on Esmeralda, they have maps of the regions you are thinking about and some gear.
If you want torres del paine and want to stay in the refugios they are expensive, I am camping and going fishing myself in that area. El chalten I will be traveling with my wife so we are staying in a B&B and doing day hikes, but camping is an option.
Do a lot more research but get that guide book, it would have saved me a lot of time looking on the internet. Getting to those places and in between can be expensive and time consuming.
Red
Appalachian Trail, GA-ME 2010