Upgrades recomendations on stock aug.

[Iceni]

Hello!

I've recently made the purchase of one of the older JG/ASG Aug A3.

The gun is 100% stock and I'm looking at a few upgrade parts specifically for this gun.

I want an RPS increase, and a single shot accuracy increase.

The stock parts that are on the gun are a little lacking but with a few additions I think it should be a good main gun.

Am I right in thinking that my best gearbox upgrade path will be:

Steel bushings
Spring guide
Shim set
Piston and head.

With a motor been an option later down the line.

And for the rest of the gun I'm thinking of adding:

Better buckings
6.03 stainless barel



With those upgrades in mind are kits like the AUG hurricane kit worth the money? This is the kit I'm thinking of.
http://www.zerooneairsoft.com/product_info.php?products_id=3268

That covers most of the basic things I was going to change for the time been but are the parts of a reasonable quality? And would it be a better investment to source parts individually?