I have one. I bought it 3-4 years ago from CDNN when they were blowing them out. I paid around $350-400 for it. I haven't, but I do plan to SBR it eventually. But regardless, it's pretty much just a fun little range toy. .32 is far from ideal for a close encounter (little green men or otherwise). But it could do the job. The actual subgun would be more ideal for anti-personnel purposes just because of the overwhelming fire out of such a small package. Honestly though. I find pistols that were originally designed as rifles to be only "fun" guns. Whether it's the vz. 61, an AR, AK pistol, etc. Throw a stock or brace on it and it becomes a "serious use" type gun.
The only way you're gonna get an optic on one is to get/find/make a mount that clamps to the front of the gun or barrel:
http://www.czfirearms.us/index.php?topic=49645.0
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Theoretically it might be possible to mount a micro reflex sight like a Burris Fastfire to the top of the gun. MAYBE. But I'm not sure if 1. it would actually work, 2. it would actually fit (with or without a folding/welded in place folding stock).But with the way the upper is designed/shaped. Probably wouldn't work. If no internals got it the way. Some major milling would be involved I think.
I fully endorse you buying a vz. 61 and doing what you want with it. I hope it works out. It's an enjoyable firearm. But you may be better served by getting one of the new Scorpion Evo 3 pistols when they come out in a couple months. Small, 9mm, an adapter for the brace will be available (no word on the actual stock yet for SBR) and plenty of rail space to spare.