As long as you put in 0.1uf for the interstage (de)coupling cap with a minimum 600V rating. For another capacitance value, you should also change a resistor.
For the parafeed cap, you can go for anything from 1uf - 4uf for 2a3 and 3.3-15uf for 45 or so.
As long as you have the 600V minimum rating.
Here's the formula for normal parafeed cap size:
C = 2*L / (R*R)
C is the capacitance in farads, L is the plate choke inductance in henries, and R is the load impedance seen by the plate (i.e. transformer primary impedance) in ohms. If you use kOhms the C is in microfarads.
This value gives the best bass extension while keeping the impedance seen by the tube's plate relatively constant and resistive to the lowest possible frequency. The value is not especially critical, anything from half to twice this value will work pretty well. For speakers with especially deep bass there may be some interaction with the speaker impedance fluctuations, and experimenting within this range of values can sometimes prove fruitful.
Edit: To save money i went with 2.2uf caps for output coupling for 2A3.
Edit 2: PB posted while i was typing.
