I got a big tack trunk from Dover. They have nice ones there, but they're pretty pricey. I'm the only one at my barn with an actual trunk. Everyone else just got like big plastic tool box type things.
Blackberry hollows has some very nice tack trunks.
I personally would look at thrift stores--unique and less expensive.
Get a Stanley tool box. Way cheaper.
I just went to Lowes and got a tool box ☺