I do not see a lot of quick strut choices for your year/model, I did find some Raybestos, but I'd not recommend them, there are some Monroe Quick Struts, but they are Struts With a L-Shaped Lower Spring Seat Bracket.
Here is a part number for the Monroe with L-Shaped bracket.
MONROE Part # 171797
For an OE ride, the best struts I see are ACDelco'*, they are 160.00-180.00 each, but they are most likely what was put on there at the factory.
If you need the AC Delco with the L-Shaped bracket the part number is ACDELCO Part # 503535RS
If you need the AC Delco without the L-Shaped bracket, then the part number is ACDELCO Part # 903010RS
Before you buy any parts be sure to examine the strut, and see if it has the L-Shaped bracket.
Let me add some pics for reference, the one on the left has the L-Shaped bracket.
2006 Pontiac Grand Prix GT with SC
1996 Buick Park Ave NA