I'm torn between a Ruger Security 9 and a Ruger SR22.
.......Two VERY mehhhhhh firearms. Not sure why you are stuck on either, but those guns are barely better than trash. And I LOVE Ruger firearms, just not "those" two firearms. I don't like any of their 9MM offerings, but their Mark 4 is a really nice world class .22 pistol, with 60 years of manufacturing history behind it.
For 9MM, look at Glock 17 or Smith & Wesson MP 2.0 (model 11521) . The Smith & Wesson routinely sells for $379-$399, less than $100 more than the Ruger Security 9 pistol, and is a MUCH better pistol. Save the money, buy the better gun. Whats $75 divided over your lifetime? $2 per year?........