Buying allot of computer stuff..

I would say go with a bigger screen, the difference between a decent one at 20" and 24" doesn't seem to be too much. I take it that was the only question you had?

 

Macs do not officially support BR.
20" appears to be at max res. If you want higher resolution you'll need another display.

 

I've never seen one. I think to go with higher res you need a 23"-24".

OS X doesn't support Blu-Ray. Unless you plan on using Boot Camp and Windows, it won't work.

 

The drive is as fast as the connection to the computer, so it depends on the interface. I rip via handbrake on the standard drive in my MBP and it's speed is just fine.

 

If you're willing to lean on Windows in Boot Camp (or in this case even in Parallels) you can rip them in Handbrake (once they've been copied to the HD using AnyDVD HD on the PC side).

I keep hoping Apple will step up to the plate and support Blu-Ray, but for now it's an area where the PC has three different players competing to one-up each other and Apple gives us chirping crickets and tumbleweeds.