BLDC control using driver with external MOSFETs
Thanks to those who reviewed and commented. Looks like MTD6501G is not going to work because using it to drive external silicon to increase power handling would remove the feedback from the windings that the device requires. 

DRV8301 or similar does seem to be the only option if you must build your own speed controller. 

The Vedder ESC is what I will probably buy for some immediate uses, and think further about experimenting with DRV8301 or similar devices - but it is going to need a reflow oven to mount so that is another challenge to overcome.