Like I said, after flipping a coin three times and getting tails three times, I decided to roll with a Muzzelite 10/22 sniper rifle build. I dubbed it "Project Uglystick" (due to its... questionable aesthetics). I divided it into four phases:
Phase One: purchasing the carbine and internal upgrades (new hop-up, new barrel)
Phase Two: purchasing a Muzzelite stock
Phase Three: purchasing a compact scope (2-6x28 or 2-6x32) and mount (M16 carry handle rail)
Phase Four: assembly and testing
Phase One is 50% complete: all parts have been ordered, paid for and shipped. They just have to arrive here. Due to the fact that first version of the KJW 10/22 got really damn scarce, I had to check all the Hong Kong shops I knew, from AirsoftGlobal to TokyoModel - it turned out that only JK Army had it in stock at a sensible price ($200). JK Army apparently has some good reputation, but what they did blew my mind: I placed an order on Sunday, Monday morning (CET) I already received a confirmation and tracking number that worked. Now these guys are FAST. Sourcing a barrel was less of a problem - even with Falcon extended barrel kit out of stock, I found a 509mm barrel for a KJW M4 that looked remarkably similar (and considering that both guns were designed by Tanio Kobayashi, I guessed it will fit anyway) at EHobbyAsia. And here's where EHobby screwed up: sure, they said they've shipped the thing, but apparently forgot to give me a tracking number. So now it's a mail race between the Ruger and the barrel, and my money's on the Ruger.
Phase Two was more of a challenge. First, the guy who I originally asked to get me the stock claimed he could send it for $12, plus 10% of the item's value as a commission fee, but then I actually checked the shipping cost via USPS and discovered there's no way to go below $48 due to the stock being REALLY FRIGGIN' HUGE. So what it weighs two pounds? It's two feet long and postage for things that large is... substantial. So I turned my attention to Ebay. Advance Manufacturing first declined to send the stock overseas, but considering they do ship other things to Europe, I convinced them to try and send me the stock. Groovy. But due to them selling some gun accessories (probably), they had some problems with those retarded monkeys at Paypal and switched to a more Australian payment processor, Paymate. Here's the problem with Paymate: it takes them FIVE *fruitcage* DAYS to process a payment for American clients. I kid you not. Also, they send you no receipt whatsoever if you pay someone, so you don't know how much exactly you paid and what was the exchange rate (hint: it's usually retarded, making Paymate no different than Paypal in this regard). However, the order was placed, the payment was made, now I just have to wait.
Phase Three is put on hold until I get everything else. I already have a humongous silencer (to cover the longer inner barrel) and my flatmate told me he has a M16 carry handle rail he doesn't need, so all I need now is a compact scope - preferably with 2-6x magnification. Those usually come with 28mm or 32mm lenses, which should be enough. Now, the problem with calibrating it is the fact that it seems to sit pretty high in relation to the barrel. If I got it right, it will shoot low at distances shorter than the one I set the scope at and high at longer ones (which isn't that much of a problem if I set it far enough to make the difference noticeable only at ranges too short to fire the gun safely (gotta love the Polish airsoft laws, you can crank your gun to insane output velocities and all you're risking is infamy in the airsoft circles).
I'm also tempted to build a Predator-style laser pointer barrel extension, with three cheap red lasers from RSOV set around the barrel, but I guess it'd be overkill. The reactions of people seeing three familiar dots on them, on the other hand...? Priceless!