I think you have a few misconceptions about my project. I would recommend you to take a look at my website.
1. Snow leopards are EXTREMELY hard to get if you don't happen to be a public zoo. What you say about getting big cats may hold true for more common species, like tigers, lions or cougars. Snow leopards are an entirely different matter, though. Building enclosures etc. might be a challenge, but it's 100% doable, provided the money and legality are there. Finding a seller of snow leopard is far more difficult, and depends on luck quite a bit. I've been doing research for the project for around 1.5 years, and finding at least a potential source for animals was and still is my greatest challenge by now. I've even been contacted by potential sponsors (or at least people who pretend to be one), but I'm still almost as far away from finding a snow leopard seller as I was when I started my research.
You are, of course, welcome to prove me wrong and show me where snow leopards can be bought by people like me
2. By "raising funds", I don't mean looking for donations. My project will be a commercial enterprise, which will be primarily based on the extreme rarity of (and substantial demand for) captive snow leopards outside of SSP/EEP. I've had a talk with a Russian exotic pet trader who actually offers snow leopards in Russia (illegally imported, of course). He asks for around $100k for one animal. As I will be selling my animals legally and w/ CITES papers, I will be easily able to charge $50-100k or even more per animal. Additionally, there will be the possibility of offering an animal encounter program, as snow leopards are usually safe enough to handle to let the public interact with them.
The investors I'm talking about won't be required to just donate money for my project. I plan to offer each of them a snow leopard, as soon as I can make them available for sale to the general public, but before everyone else can buy one. If they back my project with a sufficient sum, they will receive the animal at no additional charge once it's ready.
That's also the reason why I can't just start building enclosures etc. before thinking about where to buy an animal. Any potential backer will want to know where I plan to purchase snow leopards from, or at least whether there is a fallback option such as cheetahs. I can't build enclosures until I raise enough funding, and I can't raise funding until I have at least some vague understanding about where to look for animals.
3. Snow leopards are virtually nonexistent as pets, so it's hard to judge on how affectionate they are. But the little material that is there suggests that they are even more affectionate than cougars, and are on par with cheetahs or even surpass them. Also, there is the question of safety, which in my opinion is far more important than affection. Snow leopards are extremely non-aggressive to humans, which makes them better companion animals than cougars.
There are also quite a few commercial reasons why my project would work with snow leopards, but would not work with cougars even if they somehow turned out to be as safe and affectionate as snow leopards (which they aren't).
As I mentioned earlier, everything is described in far more detail on my website: http://snow-leopard-at-home.org
If you are interested in my project, you might want to take a closer look at the website.