Steering play solutions:
http://www.bmwe34.net/e34main/mainte...eering_box.htm
I would grab a sway bar set next.... the site linked to above has some suggestions. I chose mtech nurb. sways to stick to the whole original BMW equipment only theme, but was looking at RD ones. I think Bruno might be selling a set of his.
Strut bars.... are just engine jewelry for most situations. If you can find one cheap, and want one, by all means... but don't expect much.
I guess the next step in suspension/driveline upgrades would be a limited slip diff, bigger wheels, and bigger brakes. All this is readily available both new and second hand, which I found somewhat surprising since the e34 isn't exactly a current model.