I am not under any specific constraints. I just prefer to use fewer components taking up less space on the circuit board and I would like to limit the design as close as possible to generic parts cheaply available. My guestimate is that if the part is commonly available on ebay, then it could be considered a generic part.
I know you can control the output dutycycle by modifying the voltage on the control pin. I don't know if the range is enough for your needs.The analog output of an arduino is really a PWM signal of ~1000 Hz. It would be easy to filter it and divide it to a lower voltage to control the 555 control pin.
Even if the above does not work out for you, you should use an LMC555 as opposed to the standard 555.The standard 555 design has a shoot-through issue in the output stage, where under some conditions both the upper and lower output transistors are on at the same time. Could cause spikes to appear on your power supply.The CMOS version (LMC555) does not have this issue and generally uses significantly less power.