I've got both cameras but, given the fact that most of your photography focuses on wildlife and macro photography, the 1.6x crop of the 7D may offer some advantages. The 7D is also $1000 (USD) cheaper than the 5D Mark II which would free up more of your budget for lenses like the MP-E 65mm and off camera lighting.
It's also worth mentioning that cameras in general are bad "investments." Because replacements come out every 12-36 months and the cameras have become more consumer electronics/computers than they were in the past, they depreciate very quickly. The original 5D for example, sold for almost $3,000. Today, that camera sells for as little as $1,000. The original 1Ds provides and even more stark comparison when you consider that it sells today for $1,000-$1,300 but, it originally retailed for nearly $8,000. Lenses on the other hand, are much better investments.
Lenses can last a lifetime for many people and a lens may remain on the market for a decade or more. It is also important to keep in mind that the lens is typically more important than the camera itself with respect to image quality and for these reasons, they tend to retain more of their value for a longer period of time. For example, an EF 70-200mm f/2.8L IS USM lens of similar age to the original1Ds may still sell for $1,500 if it's in good condition. Not a cheap lens but, just before that same lens was discontinued a year or so ago, new copies were selling for $1,800-$1,900. So, here we have a lens that is almost ten years old and it is possible for that lens to have retained over 75% of it's original value during that time. No DSLR will every be able to do this but, lenses often can and do. Some lenses even manage to go up in value like the old EF 50mm f/1.0L. The bottom line is that as investments go, high quality lenses are a much better investment than the camera itself. The rule is buy the cheapest camera you need while investing in your lenses.