the weigh should not be an issue. if you want cheap rockers, I would suggest buying some 6x6 1/4" angle iron, way back when Ebay was just starting out, I used to buy a 20ft length of this material for $20; cut into lengths, drill a couple holes add about $10 worth of grade 8 hardware and sell them on ebay as hardcore rocker guards for $100, $150 with $10 worth of poop pipe welded to the side for a step.
unfortunately, this material went up in price and I simply didn't care about selling on ebay anymore once they raised their price.
I ran them on my jeep for at least 10 years and they took a beating and a half.
Simple, cheap and effective. also I would not be concerned about your motor and the weight; combined they would weigh less than 15 lbs, not significant enough to worry about it.
Here is a pic of the ones I ran on my jeep, just 6x6-1/4" angle iron, the tube on mine were from HREW tube, but Sch 80 pipe will work the same, just keep the diameter under 1.75 od.