I suggest an inexpensive card that is known to be stable. That rules out the FireGL & Quadro, for those cards the manufacturers cost extra for driver stability.
There is another way to obtain driver stability - be patient, use a card that has been out for at least a year. For example, the 5770.
Also, to test it using Mastercam & Solidworks during the time period of the return policy - so you can return it if need be.