Sorry, I misunderstood...I thought you meant pilot DRILL and countersink combined. There are things like these, but they look a bit Mickey Mouse to be honest...

Countersink Cutter - 3/32" Rivet CC40 - Cleaveland Aircraft Tool
Buy SNAPPY 7/64" x 3/8" Twist Bit Countersink For #6 Screws Fits Festool Centrotec Chucks at Woodcraft.com

I mostly prefer to lock the work piece and then drill, change to tool and countersink. Bit of a PITA but it gives the best accuracy and squareness. If it's not too fussy, I use a cordless drill.