Welcome
With Bio 20% and you will be fine. Lots of guys have ran 100% with no problems at all but that's not to say its for everyone.
As for Veggy oil I would not run it unless it was converted go bio fuel. But that is me.
Sent from my iPhone 4S
Skip the "lopey" part it is not good for your truck.
Yes you will need a V2 it will come with 2 Licenses (each one can do one ECM and one TCM) so you would be good for both truck.
Also if you buy the V2 for a Vendor 99% of the time it will come with a tune or two to get you started...
Go with the Predator it is cheap and will give you some MPG. I know a few guys that run them and love them. But it is not going to give you what you could get with EFILive but you seem to know that.