Is Bendis' Ultimate Spider-Man Better to Collect as Volumes or Omnibuses?

Long story short, I do manual labor for my old man. However, since I'm 20 years old and I'm working 3 jobs, I don't need his money. But, my old man is the type to want to pay for labor. So, we have this deal where instead of working for money, I work for comic books. I've mostly filled out my "must collect" list now but I like working for him and especially like working for comics. So, I want to collect Bendis' Ultimate Spidey (I'm buying Hickman's on my own). Would it be better to buy the volumes or the omnibuses? In terms of both quality, price, and how easy it is to collect. Also, are there any particular Spidey runs y'all think I should collect? I'm thinking about collecting JMS' run next