m777,
I've been at the Ottawa Flying Club for the last few years. The OFC and the Ottawa Aviation Servies (OAS) are the only clubs that I'm aware of at Ottawa MacDonald Cartier International (CYOW). I'm assuming you live in the area, in which case there are a couple of clubs at Carp Airport (CYRP) and Rockcliffe (CYRO). The OFC currently has a fleet of C-150's, C-172's, an Arrow and a Beech Duchess (twin). I don't believe the OAS (the club with the Katana's) has a twin ....probably same goes for the others mentioned. As you may be aware a multi IFR is pretty much essential for working as a commercial pilot, unless you're considering strictly VFR operations such as bush/float and possibly surveying.
Regarding the Katana's - I've heard may good things about them, however apparently their Rotax engines are not as robust and reliable as the Cessna Lycoming engine (though much quieter), and that was what the Chief AME at our club who told me, and he know's what he's talking about. The OFC does all the maintenance and servicing of all the OAS planes (Katana's) and one thing the OFC is noted for is good servicing and keeping the fleet in good shape. Apparently the Katana's offer a great view out of the cockpit and I think they cruise at higher speeds than the C-150. Personally, I'd be happy to have a chance to fly one. One thing I did hear is that they are pretty easy to land and so may lull a beginner student into a 'false sense' that landings are easy.
Redsnail seems to have correctly addressed your queries regarding conversions. Drop me an e-mail to my pilot prune account if you want to ask me any questions. You can even call me if you live in the Ottawa area ....
Good luck.
C.G.