What can I put sulfuric acid in?

Some plastics are specially designed to be able to handle strong acids. If you have one of those I would definitely use it. What molarity is the H2SO4?

See also: http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc03/icsc0362.htm

It is concentrated, so I’m assuming it is 18M. Strangely enough, the bottle doesn’t say.

You can do it in glass. We use concentrated sulfuric acid in glass burets and pipets all the time, along with concentrated phosphoric acid. Even if it etched the glass, it would probably be at a slow rate and I’m assuming your dilution won’t take several years complete :)
There are different kinds of glass out there too, but I don’t think I’ve seen any glass etched by sulfuric acid. I have etched steel with concentrated nitric acid though. Acid etched glass is an art form too, but they use hydroflouric acid.

Glass

Glass is fine for most acids with the only exception being hydroflouric which you need a wax lined or teflon coated container, since it will digest glass by reacting with SiO2, and will dissolve any metal it comes in contact with.

Concentrated H2SO4 will do fine in glass.