I like to go 50-50 pils/wheat, but any ratio less than that works well. The wheat brings a bready/doughy note that I like with the lactic acid.
Before you pitch the lacto, it's a good idea to adjust the pH to 4.5. This will keep any spoilage microbes at bay, and will stop the lacto from breaking down the foam retention proteins. Most commercial sours have absolutely no head retention, but adjusting pH and the wheat provides for a nice pillowy foam on the beer.
If you want it tart, maybe shoot for boiling once pH is down to 3.5-3.6. If you want it Berliner Weiss sour, the plantarum should drop it to 3.2 or less. That's SOUR!
No hops during the souring period, but whirlpool and dry hops are awesome in a lacto sour. Just keep it as flavor and aroma, bitterness clashes with sour.