Can anyone recommend an Estancia that isn't to far from BA? Also, can you go horseback riding at said Estancia and approximately for how long (i heard that one only allows about 45 minutes if that).
Thanks.
Leaving for BA in 2 weeks so suggestions needed quickly.

Folks here seem to recommend Dos Hermanos or El Ombu. If you search either name, you'll find lots of posts.

If you like horseback riding, check out this:

http://tinyurl.com/3xna57

Most estancias are set up as tourist attractions. A typical day in the country includes a gaucho display of horsemanship, lunch with entertainment (singing and dancing), and an opportunity to wander the grounds or go for a short horseback ride. There are numerous estancias that provide this type experience, Don Silvano, Santa Susana, and many others.

If you are interested in much longer horseback rids with a great lunch served in between morning and afternoon rides....Los Dos Hermanos is perfect for you!

I read a great review, on TripAdvisor also, about the Estancia Santa Susana

http://www.esantasusana.com.ar/english.htm

Santa Susana was a nice estancia. Set up as a mass tourism thing. You could see the house,,,,which was fairly small and nothing special if you have visions of some grand country estate,,,,,the gauchos had a nice horsemanship show and the asado was excellent. perhaps not the most authentic experience but enjoyable nevertheless. (the owner looks uncannily like Geraldo Rivera)

A few years ago We stayed in El Rosario de Areco in San Antonio not far from BA. The place is family run , very stylish and beautifully maintained. The kids all played polo and there were loads of horses. We got to ride for as long and as often as we wanted. We were the only guests there at the time. Meals were excellent and we spent quite a lot of time with the family. It was a really enjoyable experience.
We also stayed in the Estancia Santa Teresita in the South in Patagonia quite a different but equally thrilling experience. I strongly reccommend staying in an Estancia.