Intro to DSP. AVR or other?

I’m looking to get my feet wet with DSP. Would it be acceptable to stick with what I know (AVRs) and play with the UC3’s or just move on to TIs who have been in the DSP game for years already. I’m looking to get a dev kit and a book/guide as well if someone can recommend anything.

A cheaper option is to use a Microchip dsPIC.