You can probably get them from CZ. You MIGHT be able to get them from Mec-Gar. But the cost is quite hight that way.
Nobody else makes springs specifically for CZs, that I know of. (Wilson makes some kits, but they're really repackaged Wolff springs, as best we can tell.)
Magazines are magazines. Mag springs are mag springs. A 10-round double-stack .45 mag will use a spring that is very similar to any other 10-round double-stack .45 mag. (The dimensions are the same, the function is the same, and form follows function.)
CZ springs are one of the key shortcomings of CZ guns...
But, until you start having problems, I'd not worry about it. It may be a long, long time before you notice problems that might be attributed to mag springs.