For your Application i recommend a microprocessor because as other friends has explained about the external harwares required is less in microcontroller like rom,ram..etc but what is its capacity in the
microcontroller 4k..8k of eeprom in this what you can do ,simple controlless video adapter and you need go for external rom and ram for your application but if your are good in System side programming you can do more than what you expect...and you can use microprocessor and same external harware stuff required for microcontroller.In simple word microprocessor is very flexible(not in all case because we are talking about 8051) ,But still i recommend to go around the forum and take advice of other genius people
....Good luck