does anyone know of a good company to buy actuators from?

If you mean for pneumatics then you can use the 3 free bimbas and also buy from them.

If you are buying pneumatic actuator, best deal is with Bimba for the first 3 actuators, free with voucher, just pay shipping.

After the free ones, McMaster-Carr has a better price than buying direct from bimba.

where do you get the vouchers for the actuators?

Just go to here

thank you for the link to the voucher for the actuators