Looking For My Next Lens....thinking Macro

[redangel]

I have been in my fav toy shops of late looking at a macro lens purchase. Ideally I LOVE the 100mm 2.8 Canon. But I am all nikon so thats out of the question! I LOVE the idea of the 105mm 2.8 (pricier than canon equivelant). I want to be able to focus on the mini world, bugs and the like. Yes it would be lovely to have a dual purpose for the lens (portrait) but im not all that fussed- I love my 50mm lens I use currently. One salesperson let me loose with a Tamron 90mm 2.8 but I found it a bit plasticy and it 'shuddered' as it focused on my d90. Havent really looked at a sigma equivelant. I am trying not to buy a lens that will ultimately disappoint me for what I want to use it for. Any ideas????