I'd start off with either an expansion chamber, or nitro. That's gonna fix your shot consistancy. (just remember, you get what you pay for. Nitro will help a lot more, if you have the dough.)
You've got a nice barrel. Keep it.
Next? Speed. Grab an agitating or force-feeding hopper. On the upper-end, it's going to be a Halo B or an Empire Reloader B (same idea, but the Empire is sound-activated.) If your wallet ain't that big, maybe go with an Empire Reloader- which is basically a sound-activated Viewloader Revvy. The Halo TSA is another good option, but a little pricey for the BPS you get. Also, not quite tried and tested as the Viewloader/Reloader revvy models.
I saved the grip-frame for after the hopper because, well, what's the point shooting faster if your hopper can't keep up? There are lots of options here, including Kingman's own Electro-grips. There are also a couple conversion kits from ACI and Dragun that are worth a look. But I'd let you decide that one. There are just so many options.
Given all that, you should be good to go.