Try this link for a variety of evaluation kits starting from 99USD onwards.

http://www.silabs.com/products/...ttools.asp

I have found them to be good and they come with a JTAG interface. And most, if not all of them are mixed signal MCUs and you may not have to upgrade to handle ADC , DAC seperatley in the near future. But whether a MCU with onboard analog circuit is preferable to a discrete MCU + discrete ADC / DAC is a subject by itself. Search the forum for more on this.

Raghu