You're fine, minecraft is not a demanding game, nor is it particularly fast paced. You may want to consider a bit more RAM.
An SSD is almost a must have nowadays, as it is just a nice general quality of life improvement to any PC. If you won't be downloading a lot of stuff to that computer, swap the 320GB hard drive for a 240GB SSD.
Also, as Sam pointed out, older AMD cards have issues with multiple monitor setups.