The stock TM vsr-10 chamber is good. The stock JG Bar-10 is not so good (although it's not bad)
If you've got the bar-10, I'd get the TM precision chamber+barrel first. If you've got the TM vsr-10 already, get a laylax, edgi, or PDI barrel (these run you around $130...). If you go for the TM precision chamber you'll want to replace your inner barrel eventually anyway, but you can wait a while.
If you have the TM the stock bucking is good, if you have the JG then I'd suggest you try to find a nineball (if you can) or a firefly bucking. That's the only problem with the JG bar-10's...100% upgradeable but keeping the hop up and bucking isn't that great an idea b/c of TM's higher quality.
After that, get laylax internals in this order: cylinder head, piston+trigger sears or zero trigger, spring guide, cylinder (teflon), and then the rest is just externals and whatnot.
I've got a lot of extra time on my hands but it would have been better if you'd taken a look at the vsr-10 section of the website first. Also next time state the brand of the gun