I'm the same way my first handgun was a Walther PPQ M2 in 9mm and I love it. It has the best out of the box polymer striker fired trigger and is so comfy to hold I love walther all around.
The mr9 is a p99 to a t, aside from the slide. Any p99 1st gen mag will fit I hope you enjoy the gun as I did. Behind the backstrap on the mr9 it is actually stamped walther if that is any indication how sinilar they really are. Also holster wisr the blackhawk p99 retention fits perfectly also...
You just missed out, I sold my mr9 a few weeks back. I put 500 rounds through it without a single hiccup. I would recommend it for anyone. The only reason I sold was because I found a deal on a ppq I couldn't pass up. FYI gander mtn in greenwood had mr9 and mr40 in stock yesterday. Good luck.