Gatcod,
on-wall speakers are definitely a hot market item right now. You're correct that many people are looking for slim, wall-mounted speakers to go along with their wall-mounted flat panel displays.
The problem, though, is that an on-wall speaker is more or less always a compromised design. There's just no getting around physics, I'm afraid
There are some fairly decent sounding on-wall speakers out there, but, unfortunately, most of them are above your budget.
Having the speakers so close to the side wall is also going to be problematic for performance. You asked what most people do with a fixed projection screen. Personally, when I was running a front projector, I used tower speakers and a centre speaker on a stand. A lot of folks either do that, or they use a cabinet system to hide the speakers and either use in-cabinet speakers or just bookshelf speakers behind an acoustically transparent door in the cabinet system.
If you're determined to have the speakers up, off the ground and you're also intent on having them look good and you also want three front speakers for a low price, I would have to recommend that the best course of action is actually to spend as little as possible whilst still getting at least semi-decent performing speakers.
I say that because I basically look at it this way - either you forego the desire for good-looking on-wall speakers and simply opt for towers or bookshelves, or else you pay quite a high price for on-walls that look good, sound good, but cost a lot and are compromised by the placement anyway.
To me, it makes more sense - if you want to stick with on-walls - to just go for the lowest budget so that upgrading in the future will be easier, come sooner and you'll be out of pocket as little as possible for right now.
To that end, I would definitely point you towards tSc and their good-looking and pretty darn decent
TSAT-2000SB speakers.
Three of those will only run you $300 and I think they will fit your need nicely. They
defnitely need the help of a subwoofer. But for on-wall speakers, they perform pretty darn well. Better than a lot of other on-wall speakers - and that's without considering the price.
I would say, that the TSAT-2000 are probably your best option overall. If I were to recommend based on what I think would actually sound the best, I would recommend the SVSound SBS-01 and SCS-01 bookshelf speakers mounted to the wall, but the SVSound speakers certainly won't look as nice.
So to me, it's a choice between good looks with decent sound or slightly ugly looks with better (but still compromised) sound

To be honest, I think the tSc TSAT speakers are a lot closer to what you had envisioned when you first asked here
