with regard to the time estimate:
I think 3 full working days is a fair guess, depending on your previous development experience. Though it's hard to tell in advance and depends on what kind of code issues you are going to encounter.
As a prerequisite, you will definitely need a serial connection. You will need it because experience has shown that untested kernels newer work at the first boot :-) . If things can go wrong, they will typically go wrong. So have a serial console prepared in order to analyse the kernel boot output and to see where it breaks down.
On the coding side, there is probably not much to do. Maybe some compilation fixes or code adaptions for USB code that changed between the K4 and the Touch. My ideas about the porting process are described here: http://www.christian-hoff.com/?p=44#comment-236
If any difficulties arise in the porting effort, I'll be glad to help.
Hope this helps! Would be great if we could get this ported to the Touch real soon.