Of your choices I'd go with the 9x18. The CZ82 is an excellent quality gun, and they are available for less than $200 if you shop around. 9x18 ammunition might be slightly more expensive than surplus 7.62x25, but good luck finding factory ammunition once the surplus supply dries up. 9x18 is available both as surplus and new factory pretty much everywhere that sells ammunition (except perhaps ChiComMart). The CZ82 would also be a good choice for a carry gun when needed, the various 7.62x25 pistols and most .22 LR pistols are not good choices for carry.