Morning all! Old photographer, new to WDC...!

I have recently purchased a Nikon D3100 having upgraded my old Canon G10 (which in turn was an upgrade from my very old 35mm EOS5). The camera comes with a 'kit' 18-55VR lens, and I am looking to expand on range of lenses a little.

I tend to take landscape, building, and 'people' shots, together with the occasional live band (small venues). That said I am also getting into macro photography too. To top it all off a friend of mine (with no money) has asked me to take a few shots for his forthcoming wedding in the summer so something that can take a decent portrait shot would be nice.

I am considering purchasing either a Sigma 70-200mm f2.8 Macro which should cover most bases; or the cheaper Sigma 70-300mm f4 macro together with either a Nikon 50mm f1.4 or a Sigma 105mm f2.8 maybe.

I know I want to have my cake and eat it, but I've only got about 600 to spend on a lens/lenses
without specialising in any one area.
Comments, suggestions, or any experience with any of the above lenses would be most welcome.

Thanks in advance,