Avalon/Vfc mk18 mod0

[pistol4ever]

Hi everyone,
I'm going to order Avalon/VFC mk18 mod0. However I have some questions about it:
- I want to put a standard m4 inner barrel in it (375mm, by the way is a pdi m4 barrel compatible with this model?), what cylinder I should use?
- VFC and AVALON are the same but why the Avalon standard version is more expensive than the VFC one?
- what hop up rubber/ bucking is the best for this gun?
- what is the largest lipo I can get in the original stock?

Thanks a lot guys

[The_Redneck]

Just found this post and was looking at getting the same gun. Just wondering how you liked it and how it performed