yup. 2wd chev trucks are 5x5, as are GM B bodies, including the '94-96 impala SS.

check out the centerline wheels website for overstock...

something in the 6-12mm+ offset (so 4.75-5" backspace for an 8" rim) should work....

these are $160/ea for forged 17x8's(!)
http://centerlinewheels.com/wheel_deals_detail.php?id=13113&type=bolt&data=5-5.0

these are about $100 more
http://centerlinewheels.com/wheel_deals_detail.php?id=12426&type=bolt&data=5-5.0

for the size of the car, some 17's or 18's with tire sizes used on the LX cars (which are ~28-29" tall) would look about right...