I have a 2015 gear and have had no problem with an offset 48" tiller. You have more HP, so I doubt it would be a problem.
As far as the brush cutter, I've used both the 4 foot and 5 foot. The 5 foot gets a little unweildy, and makes the front end really light. You have enough HP, but I'd add some weight to the front. (concrete blocks in the bucket)