I want to modify my Ecotec VY. I want to get a cam, rockers springs etc. Is there a good package that you do that gives good RWKW? And how much would it cost?

Generally, we recommend only going with a cam or a set of rockers. If you're looking for the most possible power between the two then we'd recommend going with a cam upgrade instead. Assuming you've been budgeted or are able to do the work yourself. Some items that we can suggest for this upgrade are shown below:

COMP V6 Ecotec Cam and Chip Package: 
http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/CCP618/SubProducts/CCP618

Crow Cams Valve Springs (130lb):
http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/SPG601/SubProducts/SPG601

Manley Performance Valve Spring Retainers:
http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/SPG604

Rollmaster double-row timing chain set:
http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/RLM601

COMP Valve Locks:
http://www.maceengineering.com.au/epages/shop.sf/en_AU/?ObjectPath=/Shops/mace/Products/SPG603

Oil Pump Kit:
http://www.maceengineering.com.au/epages/shop.sf/en_AU?ObjectID=2767212

Please note if you were on a budget, you could just stick with a Cam and Chip package and possibly run 105# valve springs and retainers instead.