Never had a problem buying on the internet.
But you better get used to it, as for PC games..The writing is already on the wall, you'll find less and less games in standard distribution channels and more and more throught direct sale/download.
Strategic Plus are as kosher as you can get - I've bought dozens of titles from them and visited their shop many times in the Last 10 years. I bought dom2 direct (and just got a 2nd copy too ).
I don't have any connection with SPS, except for giving them lots of cash over the years