Migrate ISA 2006

Hi ,

My environment contains 3  servers ( ISA Array ) - all of them have ISA 2006 role

- ISA CS --> Windows 2003  --> Already succed to upgrade to windows 2008 ( in place upgrade )

- ISA 1 --> Windows 2003

- ISA 2 --> Windows 2003 .

When trying to make in-place upgrade for ISA 1&2 --> failed .

After consulting MS , they said I have to remove ISA role firest , then make In -place upgrade , then install ISA role again ,

After testing that at test machine --> I found that I cannot install ISA 2006 on windows 2008 as it's not supported .

So my question , can I Export ISA roles & configuration from ISA 2006 , then on new machine install Win 2008 & then install TMG then import the rules or this approach not recommended .

or anyone have another approche ?

Thanks in advance .