Drag Sled scales are somewhat of a personal choice. Most operators prefer analog scales as they are easier to interpolate and average readings. A solidly built metal scale that is physically large enough to allow two handed operation while maintaining its position parallel to the ground is ideal.
Braker Box recommends the two scales below. The Pelouze scale is available in limited numbers due to being discontinued by the manufacturer. The Chatillon scale is more expensive but is more robust and still available for order with your drag sled. Scales ordered from Braker Box will be dropped shipped from a U.S. supplier.
Contact your Braker Box distributor for current pricing.