What is the best way for a singer or rapper to find a music producer to partner with in a new indie record label?

Frankly, it's surprising that you are unable to find a producer in your own area. Didn't any of the sound engineers or people that you network with around you suggest anyone? Failing that I would suggest: Finding a local independent film or video maker and making a brief video to put online. You may attract producers in that manner. Finding other local artists and producing their albums yourself. Do you possess this ability? While producing for someone else you may be able to network with other producers who may be able to assist you. if you don't already live in a metropolitan area you might consider traveling to a nearby metro area and spend some time going to the various clubs and bars that have live music and networking there. If there are any recording labels in your area, you may wish to give them a call or send them an e-mail and they may be willing to introduce you based upon their assessments of your ability.Submitting a CD or a .wav file as a sample of your music to a major label might convince them to if not consider producing it themselves then referring you to someone with whom they have worked in the past. Place an ad in a local music magazine, alternative paper or online seeking the services of a music producer. Carefully check the backgrounds of anybody that you go to work with and be very flexible in what you are willing to do with this person. While I admire your desire to maintain creative control, you are simply going to have to be realistic about things. Investing in new artists is an expensive proposition and unless you are exceptionally talented, most producers, and thus most labels, are going to require that you prove yourself prior to handing you the creative reins. If that's something that you don't think you can deal with, you may need to reassess your career strategies.

I have been working in the music business since the early 90's and have a wall with a bunch of gold and platinum records with my name on them and have sat fourth row at the Grammies and so on, and I mention all this to inform you as authoritatively as I can that there is no such thing as a "record label startup."

The best way, in my opinion, is to get hold of a microphone (you can get a USB version) and record some acapellas.  Most producers are always looking out for vocals to add to their tracks. If you can record your own vocals at home, you can collaborate with people all over the globe over the internet. I'd suggest just going on Soundcloud and finding someone who makes beats you like and asking them if they mind if you record vocals over them.  Not, like Daft Punk or something, but look for an unknown producer with a hundred or so followers whose sound you like.

We recently launched http://Vocalizr.com to handle exactly this problem. You can find producers from all over the  world, start projects, and collaborate with them. It's the only  all-in-one vocalist and producer product available.