Any ideas what this could be, a car I am looking at ourchasing has the following mods:

Lunati Cam, not sure which cam...
Magnaflow catback exhaust.
Accell Aftermarket Ignition
Accell Coil
CAI w/ K&N Cone filter
Slightly plained and Decked heads. (Only going by what the seller told me on this one)
B&M Short throw Shifter

And new parts:
New Plugs/Wires
New Coil
New Optispark Distributer
New Front Tie Rod (Both Sides)
New Water Pump
New Thermostat
New Harmonic Balancer + Seals
New Rear Diff cover (Chrome)
New Rear Axle Seals
New Rear Pads
New ABS Relay (This part failed and ABS light is on)

The major issue with the car is the cars idle is bouncy and I'm not 100% sure why. Occasionally it'll stall, but always restart. It also seems to run rich. I've heard everything from MAF to vacuum leak to IAC to TPS to o2 Sensor. Any ideas, or would the cam (not sure which kind, just "lunati" cam is all the seller can give me) be the reason for a rough idle?

 

Has the car been tuned?