Re:HW recommendations? (Score 3, Informative)

You are better off the other way around. Pick your developer kit (based on the processor, memory, peripherals etc.). Then pick any RTOS that has support for the processor. This way, you can skip learning the boot code for the processor (or, what they call the board support package). If you plan to go with Embedded linux, I would recommend to go through a boot loader like U-BOOT. If U-BOOT supports the processor on your developer kit, you are good to go. Assuming you can get the cross compiler (build tools) for building linux image for the processor. Enjoy :)