That would be a shame as it seems like a well built system (although a bit old). I can't remember the last time i used a cassette?, I tried to use the single cd machine in the boot but it wouldn't play. I don't have an iphone i use an android device so will google to see if it can be made to work?
You can get them with bluetooth connectivity and 3.5mm jack connections... Xcarlink aren't the only ones out there if you have trouble with compatibility - but I think we do get a discount code.
The "standard" xcarlink has usb and sd card connections and will play mp3, it plugs into the cd changer socket on the back of the head unit.
You have mentioned a cd drive in the boot, so chances are the socket is used. I don't know if you can get a splitter for the 6th gen.
If I remember correctly the alternative devices are all aux based (red & white plugs). I don't think that the Bose head unit has those outputs.
Type Accord members get something like 20% discount or free shipping, there is a post about the discount in the general chat or diy section.
When I looked into changing my Bose unit it involved removing the dash surrounding the dial cluster to get at screws, I couldn't be bothered doing that so the xcarlink was the easiest option; remove the gear surround and the cubby hole & cigarette lighter, then you can get your hand in and to the back of the radio, the cd socket is on the right hand side as you look at the front.
Just to add, if you still wish to maintain the use of the subwoofer, just make sure it has a remote lead to it and the power lead and it should be good to go.