If those are available again (discontinued once) then that's about the only/best option going EXCEPT for one that Don R has made up. Search him/his posts out and check it out. I've seen and heard it. It's quality and MUCH cheaper than the Mac. I have one of the Macs. Heavy. Good quality. Relatively quiet with removeable baffle that can be "downsized" internally with a hack saw.
OEM not available. Both the Mac and Don's will bolt right up.
Carbs jetting are questionable at best. I didn't mount my Mac to a stock engine plus I'm at 6900 feet elevation.