Gonna throw another vote in for a single shot Cooey of some sort. Or, since they're available. A TOZ single shot would be fantastic.
Keeps your shooting slow and deliberate, you dont have to worry about stopping to reload magazines and they're generally accurate as can be.
A good Cooey 75 would be good choice, mine have been beyond accurate and the sights are pretty decent. The TOZ8M much in the same vain, just one less step to shooting since it cocks on close. Cooeys can be found on the low end of $150 and still get a decent shooter, TOZ8m's are a bit more in the $400+ area, but well worth every penny!