You'll probably have to upload one of those "Professional Bound" maps so we know exactly what you mean.
As for the wav question, this is what I do. Find a midi file that sounds like the kind of music you want. They've made a midi for just about any video game, show, or song ever made, plus a lot of completely original ones, so that shouldn't be a problem.
The next step is to convert it to a wav file. You'll need a midi to wav converter.
This is a good start in finding one you like. Now you can use your new converter to change your midi into a wav file. Be aware that the free trial versions of converters will usually only let you convert 60 seconds of midi file at a time, but that's not a problem, as I'll explain later. If you want more than 60 seconds of the midi, convert 60 seconds of it into a wav, then start from that point in the song and convert another 60 seconds into another wav file. Continue this process until you have the amount of song you want, even though it's split up into 60 second files.
Now you have your song wav, but not all in one piece. The next step is to get
GoldWave, which is a wav editor. You use this to combine the pieces of your song wav back together. Simply load the first wave, then load the second one in a different GoldWave window. Cut the second one, paste it at the end of the first one. Now close the second window, and open the third section. Cut and paste that at the end of the combined first and second one. Repeat until your song wav is back in one piece.
Now you have your wav recombined, but that doesn't mean it will loop seemlessly. You have to edit the song wav so that the end matches up with the beginning. Play it through until you find a part near the beginning that sounds like a part near the end. Set the start marker and finish marker (using right click) to those points, and use the yellow play button (it makes it loop so you can hear how it sounds). Move the markers until the selection you've chosen loops the way you'd like it to, and "Save Selection As" to save your new song wav. If at any point during this process something tells you you've used too many actions for a single session, you may have to save, close GoldWave, reopen it, and just pick up where you left off.
Now you would think that you're done, having a wav file that loops the way you want it to. However, the file may not be the right type of wav for Starcraft, and it will probably be so large that it makes your map take forever to download. The solution is Sound Recorder, which comes with Windows (Start < Programs < Accessories < Entertainment). Use it to open your song wav, then go to File < Properties. Select 'Convert Now', and choose format "PCM", and Attributes "8,000 Hz, 16 Bit, Mono - 16 KB/s". Your wav will lose some quality, but it won't make much difference since it was a midi originally. It will also lose
a lot of size, so your map will download much more quickly. Now hit 'Ok', and save your finished song wav.
When you upload your map to Starcraft, it should work fine. The reason you choose 16 Bit instead of 8 Bit is because Starcraft has a built-in wav compressor, but it only works on 16 Bit wav files, making them actually download faster than 8 Bit wavs. All you have to do now is upload the wav file, and make a preserved trigger which tells it to wait the song length before playing again.
It might seem like a long process, but once you get the hang of it, it's not really hard, just time consuming. I just finished a batch of song wavs I need for an upcoming map, and after all the combining and everything was done, I ended up with 15 finished wavs. Half the process is finding a midi file you really like. Anyways, if you have any questions or need any further help on something, you're more than welcome to ask
