Screen maker and gain

Much depends on the image size you plan to have. Your projector is not known for being a light canon, so you will more than likely want to use a material that has a little gain....more than a little if you go with a jumbo screen or you want to have some lights on. Just about every screen manufacture has a 1.3 or 1.25 material. If you go higher (1.5, 1.75, 2.5, 3.0, 6), you will need to make sure your projector is mounted (upside down) on plane with the top of the image so that any hot spotting will not be noticeable (unless you lay on the floor). Since LCOS projectors have plenty of contrast, a gray screen should not be needed. A white screen will allow for better color accuracy. Stewart, Da-Lite, Vutec, and Draper are all good domestic screen manufactures that cover a fairly broad assortment of screen types and price ranges. You did not indicate whether you were thinking in terms of a fixed frame or retractable, but if the latter, you should aspire to one that is tab-tensioned, budget permitting. Be sure to double-check your throw distance to screen size relationship. And keep your lamp fresh (it will be down by 50% after 300 to 400hrs). That's all I can think of. Enjoy...

There are a number of sub 10K DLP projectors that have more light output, sharper imaging, and decent contrast (though not as much native contrast as LCOS). That's the trade-off: smallish image size and soft picture but great contrast, or large image size and sharp picture, but somewhat less contrast.

How's the HP 2.4 screen perform under ambient light or daylight?

The RS46 being potentially rated at 1,300 lumens is probably not going to be bright enough for 3D on screens over 100" unless you go with the High Power, in my opinion. While these projectors are rated at 1,300 lumens, they probably display half that or less when properly tweaked. I would go with the HP 2.4 at 133" especially if you can mount the projector behind you at head level or close to head level give or take a couple of feet. The downside of all this gain is for 2D. If you can't crank the brightness down enough for normal viewing, you will have to use a neutral density filter, but, using a 133" or bigger screen and low or eco mode, plus cinema mode, plus tweaking the contrast and brightness for 2D should not require a filter. For 3D, you'll want all the brightness (lumens) you can get. If you don't use the projector much for 3D, then there are other screen options besides the HP. Be careful not to be confused by all the talk about the JVCs and 2D images, vs. 3D. Normal 2D image lovers of the past dwelled on high contrast, black as black, and detail in the dark areas of the images, but with 3D it all changes. With shutterglasses, you need brightness (lumens) first and foremost, then all the contrast and black is secondary.

I think when you see truly good, bright 3D, it will change your mind, however, there are lots of screen options for the JVC. I would explore the projector forums for existing experience with the JVCs being sold today and see what others have done and what they are thinking.

Hmm, I'm thinking based on reading reviews, that the Optoma HD8300 will deliver a brighter image than the JVC with comparable contrast.