B/W is the go. Colour cameras don't behave well at all in Ha.
The biggest question is whether you go for an AV camera or USB. AV cameras are great for broadcasts directly into a TV or projector and hence useful for outreach, but suffer from low resolution. USB cameras require a computer to view so add some complexity to the process but ultimately give far better resolution views.
http://www.skyatnightmagazine.com/as...iew-calculator
Use this tool to match the camera to your scope, The ZW Optical ASI178M looks like a good fit for your focal length.