Nah, mine's a KJW m700 in a Modelworks m40 kit, with the outer barrel swapped for the Action Army outer barrel to allow it to be threaded so I can fit a suppressor. I pretty much only use gas guns, and most of my guns are bolt actions or DMRs despite most people moaning that they're not consistent enough (unironically a skill issue...); they're great, but you really have to know what your doing, tweak them basically every game day, and you have to own a bunch of different types of gas for different weathers. At the moment I'm using green, but in 6 months time I will be using red or even black gas.
And yeah, any 7mm VSR spring I believe (so... most of them. Maple Leaf and Laylax are both 7mm springs I believe). If you want to use a 9mm spring like the Rapax ones, you'll need a 9mm spring guide, but again that's just a standard VSR thing, so any 9mm VSR spring guide should fit.