How much you lookin to spend? There's alot out there depending on performance desired and budget. If you haven't replaced control arms, sway bar links or sway bar bushings, I'd look at those too.
Complete struts assemblies are easiest. Starting with bare struts may give better performance options. However, they need the rest of the components purchased separately. Either you use a spring compressor at home (search youtube), or have a shop press the assemblies together for you.
You can get a good idea of what's available at
2002 CHEVROLET IMPALA 3.8L V6 Suspension Parts | RockAuto