At 120" diagonal, and having ambient light issues to deal with, a Gray screen is imperative. The 8350 is fully capable of supplying enough lumen output in Normal Lamp / Living Room Mode, but without a screen with a Gray surface & 1.0+ gain, even the 8350 cannot deliver an image that will truly satisfy.
Even a really High Gain white surface won't getter dun. Colors might shine through (but still not have real depth and saturation) but blacks will suffer badly if ambient light strikes the screen in any way.
Proper Lighting design and room colors can go very far toward helping to mitigate ambient light as well as the reflections from Projected light. But the screen is / will be the biggest factor.
As such....it's unfortunate but that there are no really "budget-oriented" Fixed Mfg. Gray Screens. Usually such "High Contrast Grays" come in at a higher cost than their Matte White counterparts....no matter who the Mfg. is. And Fixed Screens are, to the surprise of many, usually the most expensive...more so than Electric. And even sadder, there are extremely few Electrics that offer up a High Contrast Gray.
Focupix has perhaps the least expensive High Contrast Gray Screens.
a 125" er "Fixed"
a 120" Electric
Then there is Elite's 120" offering:
When you check the prices of those, you'll find that from there everything just goes higher....but the same Model / Type / Fabric restrictions apply.
Then of course, there remains the known issues of Waves....Wrinkles....and irreparable Damage that is not a warranty covered item.
Can there be any wonder that after just 6 months ( in 2002 )of trying to insert Mfg Screens into my Theater installations, I fled onto AVS and devoured all i could read and learn about DIY-ing my Screens? Back then, for many who advocated Mfg Screens, DIY was a curse word. But the facts bore out that virtually every Mfg Screen could be duplicated via DIY methods, and done for considerably less. Fixed Screens especially. But Retracables...we get'tem painted on as well.
Some comment how they cannot DIY waxing their Car let alone building a Screen....others are more direct and say they will pay 10x as much for a Mfg product rather that go through the "DIY" hassle.
I myself have painted 122" to 185" screens directly onto Drywall / smooth Substrates, used the 8350 / 8500 / 8700 / 9350 / 5010-6010 PJs and gotten spectacular results....with far more ambient light presence than most would ever experience. And perhaps just a few other hundreds of DIY'ers have followed suit on my examples. But most importantly, the biggest version cost no more than $240.00 to build....and far less if Drywall was the substrate.
That doesn't mean that I totally abstain from using a Mfg Screen. But when I do it's because the situation REQUIRES a "Retractable Screen" and then the ONLY ones I use are Focupix "Tab Tensioned" varieties (1.4 gain White) and I ALWAYS spray on a high performance 1.3 Gain Gray surface on 'em.
Now that's me....and those who need / want to follow suit and get all they expect and more for a lot less than they expected.
Such decisions are left to the individual to make. Research can help loads as far as getting well informed enough to make an informed choice. But one DOES have to fully understand ALL the criteria that needs to be considered when balancing a PJ's performance against the chosen Screen surface, and how both react to / handle Room conditions.
That can be all a bit too much for any who are not wholly devoted to the task of learning. So many will ask for opinions....and on these Forums they certainly can & will get'tem. But unless those opinions are based on varied and complete knowledge, and take into consideration all the know facts and criteria....they remain just that....personal opinions based on one's individual experience (...mostly the "one time" type...). Since it's almost impossible for any two installations to be identical, the variable "mileage" can be quite different. And is the nature of purchasing any Mfg Screen, once a decision is made and you take delivery....that's it. Iffin' it don't work...and it's not "broke' upon delivery.....your screwed.
All this is meant to serve as a chance for you to consider all / every option. If one is on a budget....that is all the more important a factor.
The ""Screens" and "DIY Screens" Forums are the place to be asking your questions. Be forewarned....it can be a daunting task...a "Bleeding Eyes" ordeal that can turn your Brain into something less attractive and useful than week-old Road-kill. But in the end, if patience and prudence wins out, you should be able to claim success.
Then...after several months of recuperation in front of your spectacular Big Picture, you can lay claim to being one of the truly lucky ones.