Kyle, my electrician had a similar challenge with the 320 amp meter housing end of last year that was required for my spit 200/200 service like yours, too. He got lucky when another electrician acquaintance of his had a job cancellation and had one available...and for a reasonable cost.

Your shop looks great! Congrats on getting it to where you are now! And wow, what a great looking exterior setting and building, too.