I don't even know if I should respond to this post and forgive me if I sound critical but your post leads me to believe you don't know much about what you are suggesting.
First of all, although I'm sure climbers have done it, ascending Aconcagua in July means climbing in full-on winter conditions. No base camps, mule services or doctors are available. The mountain is heavily covered in snow, avalanche conditions are usually high, the wind is violent and constant and temperatures rarely go above 0C. A solid 4 season tent would be needed, a winter sleeping bag, super-warm boots and you would have to carry all your gear in by yourself. You would definitely need more days than you have available.