I would like to buy a 9mm pistol with a target sight(screw adjustable for elev and wind). I know of 2: Sig p210 and HK usp tactical series. The Sig is not available because Germany has forbidden Sig to export any pistols.
There are plenty of used P210s available, and you don't have to import them from Germany, as the older ones were made in Switzerland. As far as I know, new P210s are still available, but they're very costly, and you'll have to wait a while. They're still being made -- in GERMANY -- and the only problem is delays in getting them. Big dollar price tags.
The SIG P226 X-Five guns, which are nearly as accurate as the P-210 series, have higher capacity, have more user-friendly mags, etc., are made in Germany, and you can buy them NEW. They come in both 9mm and .40. No import restrictions that I know of. You may have to get in line, however.
Any number of other guns that can be used for target shooting can have adjustable sights added.
The adjustable sights aren't nearly as important as a gun that has been properly refined (at the factory or by a competent gunsmith), and the use of proper ammunition. (Most shooters find a load that works well with a given gun and then don't need adjustable sights.)
Some of the guns mentioned above are still made (so new ones are available), and you can look at the top-line CZs, Sphinx, Tanfoglio/Witness, and a variety of semi-custom (Wilson, Ed Brown, etc.) 1911s. STIs in 9mm are impressive, and the only limitations with any of these guns are your pocketbook.
(Heck, even a Glock 34, which might surprise you with it's accuracy, comes with a fully adjustable rear sight.)