Well i guess it wouldn't hurt to get a price from the dealer. If its available it may not be a bad idea.
My first impulse is to say, No, it's not available as a "field-installed" upgrade, which is what Bobcat refers to kits or upgrades besides factory-only options. But, I've been out of the Dealer Info Loop now going on ten months, so I just don't know about that anymore.
But I do know, for sure, that 2-speed is entirely different motors(variable-displacement axial piston-types) with spring-applied, pressure-release wet brakes, very expensive, no trade-ins on your old motors, unless your dealer moves used parts.
New manifold and plumbing for the brakes and two-speed activation. Not sure, but may even have a different pump spec.
My guess, if they go so far as to quote an upgade, no pump: $13K-with pump-$18K. That's one of my WAG's(wild-a$$ guesses), and my wife always doubles my WAG's when I reply to her "what's it gonna cost?" inquiries.......=).
I know it's aggravating to go slow when you wanna go fast. There is merit in both your and your Dad's desired options.
At the dealer, we had quite a few 2-speed failures that were so devastating as to scare me from ever wanting or recommending one, but it mostly depends on how you run them. 2-speed is great, but less forgiving of abuse or neglect.
Just my two cents.