The nikon 1.8 lenses aren’t that expensive, the 85mm 1.8g which is very good goes for about $500 new, the 85mm canon goes for about $350. I shoot canon so I know more about their lenses but the 100mm 2.8 macro (both the L and non-L) are great lenses that aren’t horribly expensive. The canon 135 f2 is a stunning lens but a bit more expensive but there are usually lots of these on the used market. The definitive portrait lens for canon would probably be the 85mm f1.2 but that will require you selling some organs usually, the 135 f2 and 200 f2 are stunning but the 200 will require more than one organ sold. All five canon 70-200 would be excellent portrait lenses though the f2.8 versions will be better. For a cheaper option you can’t go wrong with a canon 24-105 f4 as long as you understand its limitations.
Here the D700 goes for a little less than the 5D mk II but lenses are more expensive on average. If you are thinking of trading up make sure you fondle both systems properly before you decide. For you the difference in resolution will make minimal difference but the ergonomics are more important. Both are great cameras. If I can throw a curve ball in there the 1D mark III will be cheaper, far more durable and weatherproof, miles better AF but only 10mpix, a similar but slightly worse noise performance and it weighs a lot more and a slightly smaller sensor.