It depends how much you want to spend.  The electrification kit that
I install uses a single-phase Model 650 Eurotherm drive controller made
in the UK for around £150.  But of course, it is 220-240 VAC, 50-60 Hz.
It is programmable for all sorts of clever applications, one of which
is for reduced power on reroll, and for a time-controlled period --
just right for gradual deceleration.

I think Eurotherm are now part of another group, but can find out if
required.  Just mail me.

Roger Waring - The Pianola Workshop
Solihull, West Midlands, UK
www.pianola.co.uk