You don't say and profile doesn't indicate what your Chassis is, so about all I can offer is this:
Our Jayco rides on a 2002 Ford E450. Replacing both OEM sway bars, front and rear, with Hellwig bars required NO drilling. I don't have the invoice handy, but I believe I paid about $450 total for the two, about the price of one Roadmaster bar. The Diameter and Steel in the two brands are the same. Mounting systems differ slightly.
Our Hellwig bars have not disappointed in any way. Got ours from SD Truck Springs. Here is their
Hellwig RV Sway Bars for Ford Page