Proxy Reccomendation

[Spyder2k]

I need some reccomendations on some proxy software. Here's my predicament, I've got ISA 2000 running on a network, Basic Authentication is disabled, enabling it on the firewall is out of the question. But this is required for many 3rd party programs, as they do not support the "Intergrated Authentication" (NTLM) mode.

I'm thinking I can probably use a local firewall that supports the Integrated Authentication as well as Basic Authentication. So it receives the 'basic' and passes on the 'integrated' (NTLM Hash) to the ISA. Any Suggestion for a 3rd party proxy that supports this?