I am not sure if anyone has mentioned this to you or not, but you must consider. Removing specific elements from a recording is not as simple as people make it seem. Sometimes it is, many times not. Removing noise, hiss, hum, etc is one thing. Removing actual music from the background of a stereo (or mono) recording can be tough to nearly impossible. Especially if the desire is to retain a vocal or any other type of leading sound. Regardless, neither can be determined without analysis of the source audio FIRST. In many cases the frequency (pitch) of the desired signal is shared with the unwanted signal and there is no separate tracks to consider. So for anyone to just jump in and tell you that they can do it without mangling the vocal BEFORE they have heard the audio in question is either full of it, thirsty or unskilled. Be careful before making a decision to pay for this and not be happy with the results. What I would suggest you do is take a small piece of said recordings, at least about 30 seconds. Preferably the most obnoxious parts you have. Forward that as a test sample to whomever you are planning to have do the job. See if its even possible to achieve what you desire. If so, see if you are OK with the results after audio restoration/cleaning is done to the given sample. Good Day. Good Luck!