Screen... yeah. These super-cheap ones are a false economy in my experience. There's just not enough money in a £79 rrp to make something with a decently thick screen material that has half-a-chance of laying flat when unrolled.
When you break the price down and consider VAT, shipping from China, goods handling, parts cost (electric motor, roller mech, case work, packing), plus labour, safety testing to British/Euro standards, import duty, cost of sales through Amazon/Ebay, credit card merchant charges, admin/sales processing costs, warranty support.... oh, and profit margins for the manufacturer and reseller; that's a lot of mouths to feed from a £79 screen, so ask yourself how much is really left to pay for parts?
There was a thread updated a couple of days ago in this forum where a guy had bought a Platinum brand tab tensioned screen a few years ago. That was still a budget screen, but he reported it was still looking good some 2-3 years later. His was large by bedroom standards, and I think the cost was around £250-£300. Smaller screens would be cheaper. The point is it was still about 1/2 or even 1/3 the price of the better known brands. A good buy then.
In order to narrow down your choices and get a better idea of cost, you need to start by working out the sort of image size that the projector will generate at your given throw range.
Remember that the projector is going to be generating some heat, so you mustn't wedge it hard up to a back wall. It'll need at least 20cm clearance to the back and sides to keep the air flowing past. You then need to work out the distance from the projector lens to the screen. This is your throw distance.
Most manufacturers have calculators on their web sites to help folk dial in the number they have and get the resulting screen size. Bear in mind that some projectors also have a zoom lens. This makes it possible to increase or reduce the image size a little. So, if your screen size turns out to be two numbers, that's because they worked out the image sizes for minimum and maximum zoom.
At a 3m throw distance, the Optoma will give you an image width (the side-to-side maeasurment, not the diagional) of 155~173cm. That converts to screen diagonals in inchs of 78"~87".
Looking at screen sizes, the Platinum 84" Tab Tensioned sits within that min/max screen size. That screen is £250
Re: Speakers...
Home cinema speakers don't work like PC speakers. A sound card - even a kick-ass one - doesn't have the amplification built in that the speakers need in order to work.
If you want to connect speakers directly to a sound card, buy a computer speaker kit where the subwoofer bass unit includes the amplification for the channels.
BTW; the Sony E2100 isn't an AV receiver. It's an all-in-one system. A very different beast. A-in-Os are only designed to work with their partnering speakers. If one or the other breaks, the whole system is going for recycling.
An AV receiver is something different. For a start it's a stand-alone device. People pick and choose the AV receiver separate from the speakers and sources. When upgrade time comes around, they'll keep their speakers and just change the receiver for.one with better features or more power. It's a modular approach; same kind of idea as building a PC where you might change the MB and processor but keep the case, PSU, RAM and HDDs.
