which ARM derivative to start with??? ====== ???

haello everyone...

I need to start my development work using ARM series of microcontrollers. When i was searching for some suitable options i found some versions available in local market.

•LPC21xx by NXP
•AT91SAM series
•AT91rm9200 by ?????????

Please anyone tell me which one of the above will be best to begin with. Criterea of choosing a particular are
1. source support
2. Internet support
4. Tool chain support by manufacturer or by community
5. Cost
6. Community support

And hamaal said the ARM7 and ARM9 are a bit old micro.

?Is the expresso good or the cortex.