Bottom line is steam and boiling water will both be 100 degrees C.
I think it's whatever is easiest/most convenient for you, the main thing is to get it from steam/boiling water to the former and clamped up really quick.
I use a wallpaper stripper to create the steam and some aluminium clad insulation board to make the steam chest (an old duvet draped over the pipes and chest keeps the heat in), it was jus tstuff I happened to have lying around in the garage (the duvet was from my secret cat nest
)
Del