You don't need to wall mount... just need decent speaker stands for the bookshelf surrounds that gets their tweeters to at or a little above ear height (to clear your seating). I usually like metal ones that can be filled with lead pellets, so they're heavy, non-tipsy, and resonant free. Yes, they still look stylish.
And even though you're doing 5.1, the surrounds in this configuration, are still called side speakers. It makes it easier to remember to plug into the correct binding posts when you're wiring the receiver (and power-amp if you get one) you do decide to add back speakers for 7.1 later.