I would be inclined to reach for my FR8, 7.62X51 NATO. I just really like that rifle.
The CZ527 is a good one too. My only gripe is the safety is backwards. Forward is safe, back to fire. Mine is 7.62x39. The vast majority of 7.62x39 is steel cased though. If you plan to reload, it might not be what you want. It's also surprisingly accurate in the CZ. The 527 is also available in 223. I have heard they fixed the twist so it can handle the heavier bullets now.
Although I do not own one, I have handled several of the RAR's in 300 BLK. Honestly, I think I would buy that instead of the CZ if I were to do it all over again. . I think Ruger should chamber it in the 7.62x39 and the new .277 Wolverine as well. Don't think I would like the 223 version though, I would go with the RAR Predator if I went the 223 route, just because of the longer barrel.
I am not a huge fan of the AK style rifle. If for no other reason than their accuracy. It is not uncommon for the AK to shoot 4 to 6 moa. Better shooting ones could be found, but it is just not known for accuracy. The AR platform is normally much more accurate. I have a couple of lowers, and uppers in 5.56, 223 Wylde, 300 BLK, and am in the process of building a .277 WLV upper.
Funny, I did not like the AR platform BO (before Obama). I bought one after he started all the hype, it sat in the safe for a long time. It was my I bought it just because I still could rifle. Of course I paid too much for it back then. I have come to like the platform. The 300 Blk is the least accurate of the trio I have now. But it is still less than 1.5 moa, better with the right bullets. The 5.56 is very accurate, but it has the pencil barrel and will open up with the groups once the barrel heats. It likes the 55 grain best but will shootbthe 62 grain almost ascwell. The 223 Wylde is my baby. With its 24 inch barrel and 1:8 twist it does very well with anything I have fired in it from 52 grain bullet weight on up. Plus it has the barrel length to get the most velocity from the 223 cartridge. I started using it for groundhogs this year. I have taken the "whistle pigs" out to 400 yards with it. I am expecting great things from the .277 WLV too!
And your question about the 30-30? It is entirely adequate. I have a Handi Rifle collection, and the 30-30 is in the top 5 of my favorites, along with the 223, 280, 300 BLK and 45/70.
Here is the FR8 and the 300 BLK Handi which gets most of my attention lately.