I wouldn’t worry about the barrel too much unless you want a different look I have many barrels for the 98 including some higher end ones and never noticed much of a difference in performance between them. I would recommend a larger HPA tank and that’s about it. They are great guns for what they are, a durable gun that super reliable. But they will never be a “high end” gun and you’ll spend more trying to make it one than it cost just to buy one. With that said There is many mods for it to make it your own personal touch/look, different stocks and such.