Upgrading a KWA G36?

So I've just come into possession of a KWA G36. Most of the specs are pretty nice, but I figure it could still use some upgardes. Here are the stock specs:

380+ FPS (Haven't gotten to chrono it, but I'm pretty sure it's up there...)
247mm barrel, 6.05mm +/- .03mm (Most likely not that extreme of a variation, assume 6.05mm I suppose)
9&8 steel ball bearing bushings
120 spring
Hardened metal gear set
1000 rpm motor
RoF = ~15-16 rounds/second
This is basically all the information I could find, but if I'm missing something major let me know and I'll try to find it (or you could, you might know where to look better than me)

I'm pretty much satisfied with the FPS, although I'd never complain about a small boost as a side effect
Mostly I just want to upgrade the accuracy, so my question to all of you out there is what parts would best accomplish my goal without costing a ridiculous amount of money?

Firefly bucking and a madbull barrel
18+35

or just the bucking

18

Firefly is a good choice and we do have one in stock. We have a barrel on its way also.

Firefly is a great choice! Rhino is spot on! I've messed with most buckings out there and I truely enjoy firefly.

Plus I have one on my KWA G36C, and the improvement was just astounding(the stock bucking is garbage). I'd also recommend shooting .25's out of it, I was using .23's in mine, but for the heck of it I went with some .25's, and now I'm stuck on em

I had the madbull barrel as well, but I ended up grabbing a 6.01 Promethus barrel(personal prefrence)

Although if you get the firefly, you'll want to get a firefly nub. You could use a standard nub, but after trying a firefly with a standard nub and a firefly with a firefly nub, I've got to tell you that while a normal nub works fine with it, you really won't get everything out of it that you would if you got a firefly nub (which is shaped differently).
Madbull barrels (the semi-new "black python" ones)are supposed to be really good for the price, although Prometheus is a little better. However, since the barrel's only 247mm long, putting a tightbore in a G36c may not make as much of a difference as if you put a tightbore in a longer gun.
I'd say:
Firefly soft type bucking
Firefly soft type buffer rubber (nub)
and a nice 9.6v mini battery

Get a 9.6v battery for sure, and maybe a MOSFET. I have been experimenting the past few days with some and I might be able to produce them.

He already has the 9.6v

Ah, gotcha. Well then he seems pretty well off.

A firefly nub will not fit in a G36 hopup with out cutting the nub up which will defeat the purpose.

So... no firefly nub then. I suppose the firefly bucking is still worth it though?

Yes it is still worth it and I do recommend them! I use them and love them.

Alright, so here's what I'm thinking as far as upgrades, but I want to know what the more experienced people out there have to say about it.

First, I'm going to get a soft Firefly bucking. Simple enough
Then, I'm going to get a 363mm 6.03 Prometheus tightbore barrel. It is 116mm longer than the stock barrel, so I need a barrel extension to cover it. I was thinking about getting this one (http://www.airsoftgi.com/product_info.php?cPath=30_39&products_id=4583) but I want to know if it will do a decent job of protecting the barrel from impacts and such as well as how it will do as far as reducing barrel wobble or something from movement, since I'm assuming that having an inner barrel just floating around with no support inside of a massive silencer won't really do much good for my accuracy. Thanks!

Or you can take a 50 cent piece of pvc or a copper tube and paint it black thats what i did, you can look at my gun next time your in the area, i also wrapped e tape around the barrel as a spacer so the accuracy didnt suck

So you used e-tape and wrapped it around the barrel to keep it from screwing the accuracy?

Yep holds it in place and imo has less wobble then the stock outer barrel

When I get a Firefly hop up bucking, I can just leave the stock buffer rubber in there right?