The actual pistol that Bill Ruger used as a model for his Standard pistol was the Japanese Nambu, not the Luger. But, yes, the tapered barrel varieties do look like a Luger.I always liked the look of the luger'esque profile of the regular Mark 1-4 but they never fit the web of my hand right...hence the 22/45s.
As far as the Buck Mark vs. Ruger Mark II, III, IV debate goes ... the Buck Mark is more accurate and has a better trigger out of the box. Ruger Mark (whatever variant) has the most aftermarket parts to make it as accurate, if not more accurate, than a Buck Mark. After market triggers for the Ruger are whatever your heart's desire.
Which do I choose? Having shot all the above in one version or another, including some very finely tuned Rugers. I choose all the above. If buying, I always pick the one that is available and, most important, the one I have cash on hand for.
The throw a few more ideas into this debate. The Taurus TX-22 is a great pistol for the money. The Sig Sauer P322 is also a new one to consider. But for the moment, the .22LR pistol that I'm spending the most time with is a Beretta Neos.