Midwest has a great name, but have never used them personally.
I have worked with Mike at Market Harmony and he is a great guy and deserves your business.
I did 6 figures of business with Republic metals, but never had a perfect or problem free transaction and have moved my business elsewhere. Not worth the petty BS IMHO.
I used them recently and can't say that I would use them again. Posted my experience in another thread here recently. Just be sure you know if they will be buying your items outright or if they will actually be assaying them after melt. Depends on the total weight you send for each metal type.