trying to add amp and sub to 04 suburban

[r2d2]

im trying to add a sub and amp to my 04 suburban with bose premium amplified system while still trying to keep my stock radio.i already have a aux harness to the back of the radio. i dont want to lose the aux harness. i found i harness online so that i can add a amp and sub to my suv, but if i add that harness i will lose aux capabilities. my question would be, If im able to add that harness to the amp rather than to the back of the stereo. will that affect anything in the audio. My bose amp is a Non Lux 15054673 and the harness im would like to add is a PAC C2A-GM24. the amp can be found on ebay and the pac harness can be found on pac-audio.com . if you need pics.