Speakers tend to be as speakers are.
That is, you tend to get more as you pay more, and opinions will be all over the place because speakers are so much about personal preference. For example, while I think Klipsch makes nice gear, I think they are a bit bright for my tastes. So be it. I don't buy Klipsch and have zero issue with those who love their speakers. So, if you can, go out and listen to different speakers and make your selection on that. Likewise, I love sealed subwoofers. I find that ported subs always tend to sound boomy rather than smooth. So, I got a bunch of sealed subwoofers and I don't knock those who love their ported subs.
I don't think oils and dirt really is a major factor with projection screens. I just haven't run into that as a 'huge issue' over the years. Fixed frame screens sit on walls for years. 10+ years is quite normal for a screen to sit on a wall without any issues. The only potential issues come from people who may want to touch the screen. I have no idea why anyone would touch the screen... so, I'm not sure where dirt and oil comes into play as a 'major' issue. It really isn't in a typically clean basement. Maybe run a duster over a woven screen once a year and you are good to go.
I do approve of getting a proper screen ahead of a proper projector. That is, if you have $2,000, don't spend $200 on the screen and $1,800 on the projector. Get the proper screen that will last you those 10+ years, then get the projector with whatever money is left. Even a 1080p BenQ HT2050a is quite good. Better is you can probably sell the 2050a in a few years and still get $300-$400 or so for it and use that money towards the better projector. So, projectors can be upgraded easily enough.
Of course, in a theater, there is a ton more to consider such as room color, lighting, and lighting control, as well as cabling. Perhaps my biggest demand when I install a home theater during construction is that I must install conduit from the equipment location (equipment never goes at the front of the room!) to the projector so that the HDMI can be replaced when it needs to be in the future.
But, since you asked, I've had a client with some very nice speakers (can't remember the brand) installed behind a 133" screen being viewed from 9' away using a Seymour AV screen.
I've also put Monoprice 8" in-wall 3-way speakers behind a Silver Ticket woven screen.
Really, both times, the clients were very happy with the final result. The first having much better overall sound, but the second client getting reasonably good sound for the money.
I've also had a client use Martin Logan Stealth Edge speakers behind a Seymour screen. For an in-wall setup, that was one of the better sounding rooms I've done.
martinlogan.com