Another cassette to CD OEM upgrade question

[dsmau]

Hi,
I know there are already some questions about this but I cannot find exactly my scenario in any of them.

Here it is:
My 2001 non-monsoon head unit has started doing loud noise every now and then last year and now it is continuously hissing no matter what the volume is. I unpluged everything except the power plug and as soon as I hard wire a speaker in, I hear the hissing. Therefore, I know the noise is not comming from my Ipod adapter connected on the CD changer control nor the external AMP. The sound comes out on the AMP and on the directly connected speaker. I tried playing with grounds with no success. In short, my HU is shot.

Now, I have a possibility to buy a used 2008 CD/Monsoon/Sat HU for not too much money. Could I used that and continue to use my external 4 chanel AMP? Would my Monster Cable Ipod Icruze adapter still work?

If anyone has good experiense in this area, I would really like to know what my options are and please do not just say why a Monsoon would or would not work but explain why.

Thanks so much! My radio is out and I am looking to find a replacement for it soon.

David