Ah yes, the good old chainline dilemma.
Im sure others here will be able to help you out better than I can but since I came upon this first Ill ask for some clarification:
When you say the chainline is out of whack, which is further out, the chainring or the cog? I would assume, given your description that its the chainring but I just want to make sure.
Im sure others will be able to get into more specifics but I had a similar question myself a few months back
Here so Ill get the ball rolling with what I do know.
For correcting chainline you have the following options:
1. BB with different spindle length to move cranks closer or further from bike. Watch out for clearance issues with chainstays.
2. Move chainring to other side of spider. Sounds like you tried that already.
3. Get cranks with different chainline measurement. I doubt this would solve your problem but its technically true
4. Using hub axle spacers to correct position of cog and then redishing rear wheel. Disadvantage is that you only get to use one side of flip flop hubs after that because the wheel wont be symmetrical. This may be a good option for you.
5. Use a spacer behind your cog. People dont recommend this typically I've found. Also the correction isnt that much. (This is what I ended up doing but my hubs are unusual).