like bulgy-snatch says, there are loads of upgrades from titanium pump arms, to SLIK back blocks, delrin bolts and pins to Quick Exhaust Valves. Ram's, LPR's, 3-way's (if you wanna stay mech) and even the internals are all upgradeable. You may hear about an mQ valve which replaces all your internals (valve, hammer and velocity adjuster) with an electronic valve which helps reduce kick due to less moving mass, faster cycle times, thus faster bps etc. Pretty much everything on a cocker is upgradeable.
For now though just look at getting a cheap e1 frame, or if possible and e2 frame. These come with electronic solenoids which replace your 3-way so that the gun be electronically controlled. From there look to reducing the moving mass of your back block, pump arm and bolt, this allows for faster cycle rates. Along with this look at getting a 44 manum ram from belsales plus some QEV's, this will also increase cycle rate.
Once you've got the e frame all you really are looking to do next is to reduce your cycle rate to increase the speed of your marker. Unfortunately upgrading a cocker can be a very expensive business. An e frame atm can go for around £150, new ram and QEV's around £40-50, delrin bolt is about £40, mQ valve is roughly £100. Planet does the nexus kit with most of the upgrades you need in one package, even if you get that first before the e frame you will still notice a difference in your guns performance.
If you do go electronic with your cocker then you will also want to look into getting a faster hopper like a halo or reloader to be able to keep up with your speed
All in all it could be quite costly to go the upgrade route, especially as if you upgrade one bit, you will want to upgrade another and so on, it's a never ending cycle but it is much fun if you love cockers. It may be an idea to look in the classifieds for any cheap e cockers which may already have the upgrades you require. You may have to pay out more for it in one go but you will probably save in the long run, then either sell your mech or keep it as a back up.
The beauty of cockers that it's entirely up to you what you want to do with it so have fun upgrading it if you go that route
Charlie.