They'd be sturdy and tall enough to use with your surrounds, but not the fronts. For your fronts/center, I'd set them on the same entertainment center that you're using for your TV, or if your TV is mounted to the wall, do the same with the speakers using monoprice speaker mounts.
Actually, from the reviews I've read they might not hold my surrounds very well. Mainly because of the size (surrounds in that set are 10.5" tall). I usually love stuff from Monoprice, but I don't think those would work. Any other good places to look?
I have a pair still in boxes planning to use them for monitors when we get settled in our new digs. The aesthetics aren't for everyone, and some users complain of wobble where other claim they are rock solid (I haven't assembled mine yet), but looking at the design, they should be sturdy.
Onkyo also makes a set of speaker stnad which might work, though their height is unclear. The AS240.
The hardest part with surrounds is finding something 42"+ tall. There are very few pre-made options out there. Over the years, I've used tall bookshelves, wall mounting, and even put the surrounds on the floor shooting upward (that last option actually isn't too bad, using it at my parents place right now where they have a reflective wall behind them).
If you're at all handy with tools, you might consider making your own out of wood or pipe. You could consider your stand doing double duty as a bass trap in a similar way to the GIK Pillar Trap. You could also take a 32" premade trap and just build a 12-24" base for it.