P250 pistol vs P229R DAK....
Both pistols carry the SIG Sauer name so you'll be well armed with either format.
Depending on your budget & use(s) for a DA only pistol, I'd look at these factors;
A P250 is modular & can be quickly converted from a full or compact to a sub-compact. The magazines, barrels & slides can be converted with different calibers.
The P250 is easy to clean & light too.
The P229R DAK is also a great carry or duty gun. It's a proven design & it too can be converted to .357sig or .22LR(with a after market kit).
The P229R is in wide use with LE agencies like NCIS, CBP, US Secret Service, OIGs of the IRS, SSA, DoE(dept of energy).
You can add Trijicon HD night sights, grips, match grade barrels.
If I had to pick, Id buy a new P229R DAK .40S&W.
Rusty