Bulk slide processing services

I recently finished going through my 200,000 plus slide collection. I pulled out the best/unique/marketable slides. Came out to around 5300. The remainder of the slide were donated to a major natural history museum. I'm looking at options for a bulk scanning service. Of course quality and economy are important. Looking for any recommendations from you. I've had scan cafe do some scans a good while back and was fairly happy with them.. Any help and suggestions would be very much appreciated.

I hope someone will be able to help you. That was quite an undertaking!! Good on you with the donation too.