gejlp,our first Kubota was a B-2150 HYD. It had the treddle style pedal.It took a while to get used to the operation of the tractor,and the movement of the peddle.
That's been ten years ago,since then, we are on our fifth Kubota,I would not be without the Rocker-Style Hyd. Pedal.For a short time we owned a Deere LX-185 lawn mower,it was a good mower,but I could never get used to the twin peddle set-up.
To me,the simple movement of toe-heal is much smoother than moving your foot from side-side....Just my opinion.
As far as a tiller for the BX,any aftermarket unit would work,as long as you stay around 48"-50". Kubota offers a very good tiller,but it doesn't have to be their brand,salesmans B.S. There is a lot of discussion here about the BX and which tiller,just do a search.