Help choosing a macro lens

[baseball105]

Hi guys,

I have a Nikon D3100 and am looking at purchasing my first macro lens. I'm having issues deciding which lens of the following lenses would work best for me.

Tamron SP AF 90mm F/2.8 Di VC USD Macro for Nikon
http://www.amazon.ca/Tamron-AFF004N7...ds=tamron+90mm

Nikon AF-S 60mm Micro Nikkor F/2.8G ED
http://www.amazon.ca/gp/product/B001..._cd_al_qh_dp_t

I would be interesting in photographing bugs/flowers, things at the beach etc. I understand that my camera is DX so the Tamron would be 135mm and the Nikon 90mm. Are there limitations to putting these lenses on a DX camera? The difference between the working distance of the lenses is 2cm so that doesn't really seem to be an issue, I'm just not sure if 135mm is too much zoom or 90mm is too little. Is it safer to go with a Nikon lens? I've heard the Tamron is just as good. I'm also wondering if having the Nikon would work better for me to be able to get a bit more background in the photo, but I also like how close of a photo I could get with a longer lens.

Thanks for any input you can give

EDIT: I also just realized that the Nikon lens does not have VR. Is that going to be a huge problem?