For V-Rail I would run the T2 size for your table. Any bigger is kind of a waste. The best pricing I have found is Rick from Superior Bearing. Give him a call and he should be able to set you up. He is the guy that everyone who builds Mechmates calls.
As far as the rack that is the same size that I have planned for my next build.
Number 20011 They have a $50 min order, but the amount that you need should reach that.
The pinion I found at MSC Direct for that rack. PT# 02274207
The e-chain I would check Ebay for the best deal. Search under Igus.