With multiple other plantings in the same bed, most groundcovers are not going to work very well. Ones that will - Veronica Georgia Blue, spreading hardy geraniums, sunroses or stonecrops, etc. - will not be very good for weed suppression. And no groundcover will "choke out" existing weeds and grasses - they will need to be removed before planting.

Mulching is really the way to go in a mixed bed planting. The stinkhorns are harmless and very seasonal in their appearance. I'd just ignore them........or rake them away.