"joetrotter"
I highly recommend stabalizer bars for your 135 while using a rotary cutter. You didn't mention size of the cutter but I will assume 5 foot or 6 foot. I use a 6 foot cutter and wouldn't run the 135 with out the bars. There are Check Chains available for the 135 that are excactly what you would want. I ran with just check chains before and found that while turning there was just too much sway for my liking. (Three point cutter with single wheel at back.)
There are kit's that sell just one bar, I wouldn't waste my time on those, you will end up with movement that will eventually loosen the fender bolts and end up with a floppy fender as well as a sloppy implement.
As you see in this photo I use two bars connected to brackets that bolt to the fender bolts. These brackets use lynch pins that have the option to bolt to 4 holes pre drilled in the bracket. Original factory fender bolts may not be long enough, so a trip to the hardware store may be needed. This stabalizer bar comes complete as a kit From Tisco through many tractor parts vendors, I'll provide link to one I bought, it should have the bar measurements in the description.
Stabalizer bar Kit
Massey Ferguson 135 Stabilizer Kit, High Alloy - SK100-33XHD Perfect length, and slight bend at each end to fit implement and bracket perfectly with no binding.
Check chain - perfect mount to PTO area of a MF135
I can't find a link at this moment, but will look like the one in the picture.
As to your second question. A "drawbar" to most would mean the bar that attaches to a pin up under the tractor and exits just below the PTO. I know your thinking a drawbar that attaches to the 3 point lift. If you buy one of those, YOU WILL need to purchase a device to keep that bar from spinning.