RME is probably the way to go, you are not paying for a proprietary plug-in engine and the converters are great. They also keep supporting their products, so you can keep using for years and years. The Fireface UFX 2 has 12 inputs (future proofing your system), records to usb, sounds fantastic and they seem to be back in stock. *Price edited: About £1800.
Motu if RME is too expensive (as they also sound very good!).