I don't think you should choose the course on the basis on pass %age.
Understand your capabilities, and also understand what's hard to get is more valuable.
Based on your experience, I'd suggest you CA/ CWA, you can go for practice in both options. If you can sacrifice the idea of auditing (other than cost audits), you can avoid CA otherwise you can provide more or less same services in CA and CWA.
CWA would be comparitively simpler and quicker, due to exemptions available (Foundation/ Practical Training). Also, it would be time saving at this stage compared to CA. If you enroll by June 5, and complete necessary formailities, you can appear both groups of Inter in December 2011. If you pass both groups and again complete necessary formalities for Final, you can appear in December 2012, if you pass that too, you are ICWAI final qualified by March 2012.
In CA you start with CPT, need to pass IPCC next, i.e. after 1 year, join articleship for 3 years, appear in final during last 6 months. If you pass all levels in single attempts you will still need atleast 4 years.
You can take classes for both courses, it's your choice, also you can do it yourself as they have postal schemes. You can enroll for both if you so desire. You can ask some student around you, doing these courses, have a look into the course material.