Is it feasable to install a smoke system for a GP Spacewalker with a Saito 91.
Any comments on what might work

As long as you can keep your wing load down (I use a 6 oz tank) it should be ok. I installed a relatively inexpensive one in my .91 Saito. Found directions Here

The only probem is that I still haven't got this tried out yet. We've had crappy weather for a maiden flight of the plane this is installed it. One point that was told to me, just make sure not to drill too close to the head on the muffler pipe; otherwise backpressure could suck in some hot smoke fuel.

Nuker

Thanks for the info. Think I might give it a try on the SpaceWalker.
Let us know how your conversion works out!