i called up Dell to order a Dell vostro and i asked if i could choose and other grafic card instead of 8600m becouse i heard it was defected and the said 3470 but it would cost $20 more so is it worth it if i'm going to use it as a hackingtosh

Get the 8600m. The mobility radeons don't work. It's defective, but it still has a low chance of breaking - and is covered by warranty.