Depending on what kind of porting you have ONB or any other porter do, the reed cases generally do not rev any higher. The TS cases generally just have better low-mid range power and response, not that its needed with the 30.5s. I would be pretty surprised if the full mod 30.5s hit 20k, i personally think that 19k is more reasonable estimate. Either way, should be a screaming engine with tons of power.

Trevor Simpson is the only person that I know of that makes a reed crankcase for baja application. ONB (and I'm sure other people do as well) sells engines that use a regular crankcase with the reed block on them, look at the "cylinder reed ported engines" section on their site. As far as being better, that depends on the person. There is a pretty big price premium for a case reed engine. Because of the reed valve the powerband is wider, hence the better low-mid range power. The top end is approximately equivalent between a piston port and a reed port of equal bore and stroke.