Wood is generally only used as an early-game ingredient (wooden power poles, wooden chests) intended to last only until Logistic Science and stable steel production (medium power pole, steel chests). Perhaps replace it with an iron plate?

This item requires plastic and thus should be a Chemical Science technology, even if it is a direct upgrade to barrels. I suggest a 200 x (Automation + Logistics + Chemical) research cost, with Fluid Handling, Chemical Science Pack, and Logistics 2 as prereqs, for balance.

I added wood to kind of represent the wooden pallet some of these tanks sit on, but as I've gotten some feedback, I'm having second thoughts on that.
I agree on the blue science pack, too. These are kind of endgame items that make robots able to move fluids pretty fast, I'll probably change that in a bit here, but I'm thinking of making the wood requirement a mod setting. rather than just outright removing it

I agree on wood being a less than great requirement. Not least because there is no way to reliably make it in vanilla indefinitely. Well... no ressource is unless you forage further out to access new patches. But wood, for most players, is known as needed within the first <10 hours of play at worst, and shot/exploded/nuked once you outlived small power poles.

Enter people like me: I prefer to play maps with all enemies and trees off, so that I don't have to concern myself with these while building huge bases. And if I'm going to use a mod, I'm certainly not beyond spawning those first few wood/poles via console.

If wood was replaced by iron (or more steel for a simpler recepie), I'd be tempted to give this mod a go!
To further my point: I know IBCs from my job, and have rarely seen them with wooden pallets underneath. Most ones I have seen in real life just go with metal studs that match the pattern pallets make to ease handling with fork lifts. I guess it's just more economical to weld another piece of metal to the thing than introduce a whole different material and manufacturing process. (Or delivery chain if bought from elsewhere.)

Great idea and job though! Especially as a first, and even more so for being so mod-friendly!

Yeah, I already swapped out the technology requirements and took the wood out, I figured plastic is complicated enough, wood is just kneecapping its usefulness for "mass storage".

Yay! <3