There is a lot of hype about the difference between OSC and Mono CCD's but from my experience a lot of it is purely hype. If you choose to go down the OSC road you wont be dissappointed. When you look at the time differences in imaging with one against the other, processing one compared to the other and the overall end results with all being equal there is not an awfull lot in it.
Dietmar Hager did a comparison and has posted it on his website and here on IIS which gives some insights into these supposed differences. Well worth the read.
http://www.iceinspace.com.au/63-460-0-0-1-0.html