Koperski rhymes with:
kasperski, persky, dworsky, figurski, gerski, girsky, gurski, gursky, kasperski, kuberski, mirsky, persky, podgurski, stachurski, swiderski, swirsky, turski, twersky, tyburski, yaworski
Koperski sounds like:
kasparek, kasperek, kasperski, kasprowicz, kasprzak, kasprzyk, keepers, kippers, koppers, koppers', koprowski, kosberg, kovarik, kozberg, kuberski, kubrick, kubrick's, kuipers, kupres