As long as you have sufficient lighting for what you want to keep, I'm thinking it shouldn't be a problem. We use the terms LPS and SPS more out of convenience for the hobby. In scientific texts, they're seldom differentiated. In other words, they're both stoney corals, so as a general group, there's no real reason to differentiate them. On that note, from what I've seen, the stoney corals seem to be the easiest to mix. As long as you keep them from touching each other, you're pretty safe as far as compatability goes. The rest is just making sure you can provide for the requirements of that particular coral. Although we tend to say LPS need less light, less waterflow and are overall easier to care for than SPS, that's certainly not always the case. I think the soft corals are going to be more of a potential issue, but even there, mixed reefs don't seem to be particularly uncommon, so it can certainly be done.
Anyway, take that for what it's worth from someone who's only been doing this about a year and doesn't currently own any SPS corals. Very nice setup by the way!