I'm not sure about the e28m30 engine mounts but I tried 11811129286 from the e30m10 as per someones recommendation, they look very similar to each other. Well, I wasn't happy with the construction or the way they fit so I ordered in a new pair of original BMW motor mounts. I can't see any reason to try and upgrade here, the engine is very secure but insulated.
I do recommend the e21m10 transmission mounts 23711175424. They are an upgrade in bolt size and dampening, as a bonus you can add AKG top hats for added rigidity. With poly or aluminum transmission mounts I would be concerned about the carrier bracket ripping out of the underside of the car.
Did this all last summer, It was fairly easy. e21 mounts in combination with new motor mounts should improve shifting and engine response if they are due for replacement.