Lenses for a nikon D7000?

I have been taking photos on a canon 400D since 2007, using a standard 18-55mm and 75-300mm lenses that came with the kit.
i'm now looking to upgrade to a nikon d7000 as it is what i'm looking for compared to the canon 7D.
but after much research i'm having trouble picking lenses… I take alot of photos of animals, plants, portraits in low light most of the time. I want to get a macro lens, aswell as 2 other good lenses, which compensate for how i'm used to the lenses on my canon.
also if you know any other good equipment i should consider, please contribute.

The Canon 7D and Nikon D7000 both have their advocates. Certainly your old collection of Canon lenses should not hold you back from switching brands, because they are not good enough for the 7D's 18 MP anyway. Probably good choices would be the Canon EF-S 15-85mm IS or the Nikon 16-85mm AF-S VR for your wide to slight telephoto zoom. For longer telephoto get the Canon EF 70-300mm IS or the Nikon 70-300mm AF-S VR. There are several good macro lenses to choose from. The Nikon D7000 would be compatible with the AF-S and non-AF-S Micro Nikkors, but the non-AF-S models have gotten less favorable reviews. Probably 60mm would be a good choice, suitable for portraits and plants. A longer focal length has more working distance, favored for insects, but its shallower depth of field would be a disadvantage for plants.

Nikon sells the d7000 with the 18-105 which makes a nice combo. Add a 70-300 for animals outdoors and a macro lens like the 60mm and you're set to go. Save up for a tripod and a flash.