Controlling 3 phase 115v 400Hz servo motors?

Happy New Year everyone!

I have a roller blind presentation artificial horizon from an EE Lightning. It wasn't long before I started to to take it apart and see what was going on inside.

At this stage I've removed (and stored) all the original solid state circuitry, The plan (at the moment) is to use the original servos and lighting of the unit.

For several reasons I'm not keen to swap them out for DC servos, I don't want to replace all the servo motors, some are in very tight spaces then there is the consideration of the torque involved to move some fairly involved mechanical drives in the instrument. There is also a certain neatness to the concept of keeping them, all the original circuit boards unplugged from what looked a lot like standard LPT/Parallel port style connectors, this leaves me with all the wiring and the servos in place to drive the instrument.

So I am hoping to find a suitable PC compatible encoder/board. The unit also contains a Syncros unit, this I assume is for returning the position of the roll indicator (the whole assembly of the roller blind rotates to indicate roll). It would be nice to somehow make use of that too.

So where do I start? I've been searching the web for information, some of the theory is beginning to sink in. At this stage an off the shelf plug and play solution would have a lot of appeal, but I'm not sure if there is one available for 3 phase 115v 400Hz servo motors?

I will need to be able to control a good number of them too, there are several of these servo motors in this instrument, and plenty more to come as the project progresses. So any thoughts on what I should take a look at? I'm looking to run the instruments from FSX.

I have posted this elsewhere on the web, though I've found with some of the specialist cockpit building forums one gets plenty of views but not too much in the way of replies.