Silver Shoes, Martin Industries l.l.C. makes markers similar to what you are wanting.They build them for JD750and1560 drils. The 40' marker set has a list price of $2995.00 and includes;hoses,cylinders,and automatic sequence valve. They are definitely heavy duty and have a break away design. If you are interested,let me know and I'll get you my price on them. Hyper Harvest II