I have used Wilger tips for many years.  They have the best tip charts in the industry.  You'll know exactly where you stand on average droplet size, percentage of driftables, and percentage of droplets that are too large.

This may not be what you're wanting to hear, but here are my thoughts.  I know that a lot of guys use one nozzle for all situations, but I'm not a fan of that.  Chemicals are expensive and I want to put them in the best situation possible for top performance.  Contact herbicides and fungicides need smaller droplets with excellent canopy coverage AND canopy penetration.  Systemics such as glyphosate often need lower spray volumes with higher chemical concentrations in the droplets as long as you have coverage.  It would also be helpful to know what pressures that you want to spray and sprayer speeds for each type of spraying.

I use a twin nozzle (forward/backward type) for fungicides and products like Liberty, Gramoxone or Sharpen.  Wilger didn't have a twin at the time I purchased nozzles so I used an adapter and the Twin Turbo Teejets.  I like pressures around 40-60 psi and volumes of 12-18 gpa depending on the product.  Flat fans can work okay, but twins are better, and I need two sets of nozzles anyway.  I use an MR110 for everything else usually at 30-45 psi and 10-12 gpa.  All of this is with an AIM system on my sprayer.  Another thing to consider is the max speed of travel.  I like to select a nozzle for 95-100% duty cycle at max speed so that when I slow down for various reasons I can stay above 50% duty cycle on the AIM system.  I wouldn't get hung up over the ER, SR, MR, etc. as long as you get the droplet size you want.  Wilger also has an excellent tip wizard on their website and they are great help over the phone.

Hope this helps,