RE: Making some Parallette bars?
those pictures you have up just seem to be made of 40mm pvc pipe.
if you wanted to make them yourself look in b and q along where the sink traps etc are. you will get the bits there.
dont know if i would trust it to hold my weight though!!!
any metal fabricators would weld you that up in no time at all.
you know anyone in the trade?
failing that, if you went to a plumbers merchants and got the fittings in black iron, that would definatley hold you, but you would need a friendly plumber to thread it etc for you.