The best thing to do is try out some different models and ask advice at your local club first. I am fairly new so cannot give a detailed response, however I decided to go for a Feinwerkbau P70 as my first rifle for 10M after trying someone's at the club and seeing how adjustable it was to adapt to most people.
Regarding the Walther, it seems a fair price and I would be tempted as I like the look of it and it is close enough for me to try before buying. If you try it and get on with it, and can afford/justify the price then it is worth serious consideration.