The first thing I'd try would be to send them native DVCPRO HD. Final Cut Pro and Avid both deal with this format (in different ways) and likely the post house will have one or the other to then format it an AVI.
But frankly, I'd be distressed at the request. AVI has been officially obsolete since 1996, when Microsoft knifed it. There are much better alternatives and AVI workflow between Mac and PC is very, very difficult. I'd be very suspicious of any "post house" asking for AVIs at HD specs. (There was no HD when AVI was stopped being developed).
You really have only "None" as a codec choice that will stand a chance of being read at the other end, and you'll need to keep each file under 2GB (hard with uncompressed) as that's the original AVI specification (third parties took it beyond that but the last specs published by MS were at 4GB and the last supported by QT is 2 GB).
You will not see any difference between PSF and progressive. PSF is simply a way to put a progressive signal in an interlaced carrier, and you're no longer working with interlace in that sequence or in the digital files you export.
Ask about an alternative delivery format.
Cheers
Philip