Planning an Argentina vacation

The vacation will be between 3/12 and 3/22. I would like to visit Patagonia, Torres del Paine National Park, and Puerto Iguazú (time restraints may cause that to vary). How would I get there without purchasing a packaged tour? I understand the rail system is quite intensive and car rental is possible. Are there any cities that act as thresholds to these national treasures? If so, how would I go about getting to those cities?

I am currently planning the visit. Any information would be helpful. Transportation is the biggest issue for me. I just need to know how to get to these places after I get into the country itself.

Thanks for your help.

Hi,
I'm a local, and I've travelled all around my country.
Forget trains, argentinian rail system is from quite bad to incredible bad
Buses and planes are the way to travel to cover such long distances.

if you are on a budget, use buses. Overnight buses will be the best option to travel sleeping and don't feel the long hours (and save that hotel/hostel night).
Here, most you pay, better service you get, I mean, if you can afford the best service, do it! it will be a lot cheaper than flying yet. But if you cannot afford it, anyway you'll travel fine, just not luxuriuously.
yes, luxuriously
going to Iguazy, try to afford it and try the "Tutto letto" service by Via Bariloche bus company. The seat gets completely flat. The second best service (same car) is "ejecutivo", is still amazing. Believe me or not, at night, last hour, the steward goes offering a glass of whisky or champagne. I travelled a little abroad, and I know this service in my own country can't be beat easily.

Usually people spend 2 days in Iguazu, one day for each side, and please, visit brazilian and argentinian side, different experiences. But in fact, if you can devote one more day, better. There are other places to visit, and if not, the falls deserve to be visited more than once
I've been in Iguazu 3 times in my life, and I'll go back again, maybe this year, to take the Full Moon tour, which is expensive, but a friend of mine took it and got mesmerized by the white rainbows under moon light (only possible full moon nights, no rain)

which parts of patagonia have you in mind? it's very big, what do you prefer? mountains, woods and lakes, glacier area, coast? wildlife?

this probably will help you

http://www.viabariloche.com.ar/home/

the same company owns Tigre Iguazu. I used once this service because Via Bariloche sold out everything... and even when the service is good, they stopp in almost any town, what makes the trip still loooongggeeeerrr...

Via Bariloche goes to south, to Bariloche also, or course, same great service. Very recomendable.