man, the friend above AmrZohny proposal is fabulous, beyond that, you'll see on your development focus, today has many 32-bit cores, each with a deversidad of proposals in relation to the cost benefit. ARM11 ARM7 ARM9 Cortex1 AVR 8 etc etc ... then you should also see the tools necessary for the development or learning to use them, these costs, some manufacturers give you free tools very good quality, while others are more expensive, this should be analyzed. I sincerely believe that no one will tell you use this or that, because nobody knows your inclinations and tastes as well not your purchasing power