I would be very very surprised if you managed to produce a significant amount of shake from a 3D printer, especially while printing. If you’re busting rapids around, it kinda doesn’t matter. I run a CNC router with a 4 lb spindle on a 2x4 base without much trouble.
You can research some “torsion box” designs if you want to go to town. 2x4 stock isn’t great and will likely induce some degree of warp as it dries, but you can mitigate this by picking out riftsawn and quartersawn pieces . Plywood strips can also be a viable strategy.
I’d just grab some metal shelving from Costco or Home Depot. By the time you have your mountains of filament spools, it’s going to be industrial looking anyway.
I would also start sooner on looking at negative pressure machine enclosures if you’re getting serious or it’s in your house - UFP emissions, particularly from ABS, are a safety question mark. That angle would push me towards 8020 extrusions.