DIY - Cavity sliders/sliding doors/pocket doors

folks, has anyone made their own cavity sliders/pocket door frames? we are cutting through a bedroom wall into an empty space and will turn this into my daughter's wardrobe. the walls are non standard thickness at around 100 mm. was thinking that i could use 70 x 35 mm studs laterally on either side but 70mm plus 40mm door plus gaps is going to make a very thick wall and will waste some space. What timber should i use? the frames i have bought before all seem to be made out of thin hardwood or aluminium.

IMO it is not really worth the hassle, you can order them for different thickness walks but for a one off job like yours I would just replace the jambs for wider ones and pack out the cavity slider frame to suit your stud width

cheers beardy. was it simply red who sang "Money's too tight to mention..."? am hoping to make them from materials i already have. might go down to the big hardware shed and measure one of theirs up. that should give me enough to go on.