760G Chipset have Radeon HD 3000 integrated in them. It's probably equal to an Intel GMA X3500, Radeon 2400 or Geforce 8200. If you want an upgrade you can go with a radeon 6xxx cards based on the budget. Or you can wait for the new radeon 7xxx which is probably going to be released on the Q1-Q2 2012. It will give you better price/performance ratio.
Thank you - that is exactly what I needed to know.