Ok so I'm planning on buying a Modify Mod24. I only want to upgrade the barrel, hop up unit and spring. I want to get it shooting around 450fps. I wanted some input if there was anything else I should upgrade or change out? I'm new to the world of airsoft sniping. All tips and tricks would be appreciated. Also I've read a lot of the guides on these rifles I just want some input from everything so I can make some decisions. Thanks!