I have a map from my Bros 07 RG where he had a proper dyno tune done by some one good. We have the same pipes and breather. He was running S&S 583 cams and I'm installing Andrews 48. I'm wondering if I should use his map as a base then auto tune or just auto tune from my current map that is based off of ac, breather and no cams.

Also he had wide band sensors and I have narrow. Not sure if that will create a problem?

You can sure try it. It is no problem to just store it in one of the slots if you don't like it and flash something else.

The map would flash as long as your bike was a 2007 model which is a one year only specific calibration, if your bike is any other year it will not work. If the map was configured with wideband O2's it would have the closed loop stuff turned off, you would need to reconfigure the AFR table and closed loop settings as well.