HorseFly,
The above mentioned Yo Dave kit works fine and is the cheapest route you can go... got one gun with one of these and two guns with the adjustable sear (Brownell's carrys them). Like the adjustable sears better (quicker to adjust sear engagement), but both work fine, they run around $55. Timney and Rifle Basix also have replacement triggers for CZ's they run around $80 (not sure exact $)? Brownell's have these also. You may see some bad reviews on the timney's... when they first came out they had some teething problems but this was taken care of long ago, i have heard you may have to route a little wood out to get them to fit.
Don't ignore those irons... they make the Lux and the Trainer (same except has a beech stock) the two funnest of the CZ rimfires by far. I use the in-expensive B-Square rimfire sport utility rings which are quick to remove and replace (with no loss of zero). Picture shows a Weaver 2-7 power rimfire scope with the above rings (low's) and mediums pictured above the scope. Mine also has the ghost ring replacement blade in the rear, someone over a rimfirecentral sells these, don't know who as I got mine years ago.
Jerry