If I could find one, my first choice would be a CZ 453 for the set trigger. Second would be a 452 and use something like a Yo Dave spring in it. 457 MTR's are popular as well as the Tikka T1x.
At the end of the day, as with any factory gun, one single example of any one of the above can probably outshoot any other version of any other one from rifle to rifle. I prefer the 452/3 lug setup vs. the 457 which Glen has outlined on RimfireCentral as well.
You will have to find the 452/3 used, but I would make an attempt to find one, preferably the varmint model in those two although any of them could be excellent shooters. At the same time, there are no guarantees, but in general they are mostly all good shooters. If you can shoot one first, always best. If you can't, I think your odds are as good as any with the CZ as any other.
I have said on others forums as well, I think any of these factory guns are capable of shooting 2500's on the factory target. It is quite forgiving with such a large 100 circle. If you have shot unlimited and learned to read the wind a bit, I think you could do quite well in factory with any "decent" rifle. It wouldn't even have to be great. If you are using good ammo, any of these guns can shoot the approx 1.5 MOA to keep things in the 100 ring. Wind will be the factor most likely, not the gun.