Meh, everyone goes for the Nikon route, and that's understandable. I've shot Nikon for many MANY years (D70, D200, D7000), but lately I've been on a Canon rage. The Nikon works well with high ISO situations, and I used it for that very purpose. With reptile photography, it's all about lighting and hitting it with good light or using natural light.
For a good introductory setup this is what I'd reccommend, it's going to cost around $1800, but the beauty is you can buy it piece by piece, or check craigs list for the lens and flash...
http://www.bhphotovideo.com/c/produc...i_Digital.html
Canon T4i is a great little camera, that offers a lot of the features in the higher end cameras, but not as good of a focus system in some terms (hence the price cut from its far superior 7D and 60D big brother and sister). But it has a touch LCD pannel and the LCD screen can be flipped and rotated around to make odd shooting angles easy to work around. It also has GREAT HD video, which you may want in the long run. Can not go wrong with this body, but be warned the price is $850, and does not include a lens.
http://www.bhphotovideo.com/c/produc...USM_Macro.html
Best macro lens on the market for Canon that is not a bazzilion dollars. The only difference between this model and the next one up that is nearly twice the price is the fact that it lacks image stabalization and it does not have the Lord Red Ring around it to signify it as an L series (Lord series) lens. This lens will carry its weight, and retain resell values for years to come.
http://www.bhphotovideo.com/c/produc...acro_Ring.html
Cheapest alternative to a full blown light studio. This thing will produce astonishing images with ease. The price tag is quite high . . . but this flash was made for the lens above. You will see good results!
Ok, so that all may be a little bit too much for starting out, but it's a goal to head for in my thoughts. You can start out with the slightly older Canon T3i, and have fun learning with it, add in the macro lens next, and then a solid flash set up. That would reduce your cost a good bit, but also be like a payment plan as you add as you go. Other things you could look into would be mirrorless cameras. They fit the niche for those who want a DSLR style camera, but aren't ready to commit to the big camera, but still have some manual controls. I use the Nikon J1 for portable fun shoots and it works pretty good! Nikon just announced the J2 however, but even so, without adding a macro lens the macro on it is sub par and lighting is difficult to attain.
My two cents.