Forget replacing any of your current gear for now, you need to setup a rig that can mimic what a scanner does for paper. What this entails is building an elevated gangway that can be rolled over the carpet when it's placed on the floor. The underside of the gangway would need a few identical daylight balanced bulbs to illuminate the area, with a camera port in the center. Use black fabric or foam board to seal off the front and back so that you're constantly shooting with light just from the bulbs on the underside of the gangway. Setup the camera to shoot tethered to a computer so you can review as you go. Get a ColorChecker to make sure you're absolute on the tones being conveyed by the photograph (designers will love you). Roll the gangway over the carpet, shooting as you go. If you have taped out the center line of the rig, and have the space, you can be shooting one carpet, as assistants roll up the previous one, and lay out the next one. To get a 'full carpet' photo, most software can do a panorama stitch of multiple photos, just make sure you have alignment marks that can be used colored blocks that would be cropped out of the final photo.
Most of your shots will be at ISO100 and F8, with your shutter speed calculated off of how bright you setup the underside. The kit lenses are fine for this - check out most mall photo booths, they use the most basic kit with a proper flash. For your setup, I'd recommend the daylight bulbs just so it's a constant light source that shouldn't change over time. 2000 carpets every 3 months, you want a process that's straight forward and always the same.