a 1/8 wide strip from a glad sandwich bag is an excellent substitute. The original czech nymphs use salami skins for the shell back.(per the book)
if you can find the book in the USA, get it. it has the history of czech nymphing and lots of patterns. http://www.amazon.co.uk/Czech-Nymph-.../dp/8090388213
you dont need fancy hooks from the czech republic either. simple scud hooks from tiemco, mustad etc are perfect.
you dont need fancy weighting for czech nymphs. ordinary lead/non lead wire is also perfect.
if ya gotta have magc foil heres a place in the USA to buy it: http://www.flytyingspecialties.com
Google "czech nymphs" for tons of info