What Altera Dev board should I get?

Ok I see, for some reason I thought the Avalon bus was a separate Altera IC. But it is just their embedded bus on the fpga. I will read the Avalon document.

I'm an EE with some experience coding on TI microcontrollers. Our current designs use microcontrollers with FPGAs as co-processing/routing. But for this design I would like to have a embedded SOC on fpga.

What do you think are the pros/cons of using NIOS II vs. a separate microcontroller, besides space?