NeoPixels have the advantage that you can control each led individually. If that is not a requirement (you only want to dim / on / off), you can opt for simple led strips (one colour or RGB) that you can drive using PWM. You will need some additional hardware (FETS) to drive them but you don't need massive memory.
No idea of the cost difference, you will have to do the research 
Whatever you decide, you will need a solid power supply.