Or, if you are handy, do like we did on my garage.
We found a dealer who would sell us the right springs and all the heavy duty hardware and he told me what size to make the door panels. All he needed was the weight of the doors minus paint to match the springs.
We used 2X4 lumber for framing the panels and insulated them. Both the inside and out got MDF screwed to the frames. MDF loves paint so we used a good primer/sealer. On the outside, I used cedar to make the door shapes, then added metal hardware in hinges and door handles.
If I had bought the doors (2), it would have cost me over $8K. I think I spent less than $1K so I had money left for other fun stuff in the garage.