I'm with Isobel & MartyH, maximise your vertical storage to the absolute hilt, because then it allows more opportunities to optimise valuable floor space.
Your idea of having cabinets on wheels is something that I've done, I used (second-hand) steel filing cabinets.
One is a 2 draw lateral, fitted with lockable castors. The only trap, is that if you load heavy items into the drawers, it can (tend to) tip towards you when drawers are opened, in which case you maintain your grip on the recessed handle to keep it stable.
The other is a pairing of 3 draw filing cabinets, siamesed back to back with pop rivets, which alleviate the tipping forward problem, & then I fitted locking castors.
The beauty of this system, is that the 2 drawer lateral, & the back to back 3 drawer cabinets, are mobile, different heights, & are stable when locked in place. This all adds up to very flexible storage & work surface.
When they aren't needed, they can be moved out of the way, if you need floor space.
In fact, with that flexibility, I wish that I'd thought of it sooner, in which case, rather than my fixed workbench, I'd rivet several 3 drawer metal filing cabinets together & fit lockable castors, making it super flexible & storage efficient.
With regard to the 3 pics that Isobel posted, it comes down to your preferences. If you want storage to look nice & be space efficient, then go with Slatwall (the first pic), but do not buy new (expensive much), as there're plenty to be had on Gumtree at significant savings.
A similarly space efficient & flexible system as suggested by MartyH, is pegboard, which is waaaay cheaper, but not an eyesore.
If funds are an issue, then Isobel's other pics are perfect. I can't imagine that you'd be able to get cheaper materials to be as functional, as pallets.
