If you're new to airsoft (meaning you've not really played much before), i'd recommend not buying a sniper as the videos online you've likely seen are of players with lots of experience and lots of money invested into their rifles - most of the videos i've seen have their snipers running on HPA too. Snipers, especially spring rifles, are 'built not bought' unless you're going to buy someones already built rifle that they're selling on but even then, there's no guarantee of it working as it should <- found this one out from personal experience Turns out the guy had spent ~£40 on a hop unit that just didn't work well with the rifle.
It's my understanding that most snipers, out of the box, require extensive upgrades to make them viable (some more than others) and AFAIK they're often sold with a spring inside that only outputs 1 joule. Additionally, accuracy and range on the stock hop units and hop rubbers is poor to questionable. AirsoftCamMan has a good video where he uses a stock CYMA VSR and a stock SSG10A1. This will give you an idea of how they are without upgrades. It's not totally clear if he's put 500fps springs into these guns so take it with a grain of salt.
Even when you get to the point of having a well built & tuned sniper rifle, it's still airsoft and you're still shooting plastic BBs that will skew off at times and miss the target even if you do everything right.
To answer your question about rifles: the most recommended i've seen is the Tac-41 Lite Sport then the Novritsch offerings.