Hey Rob, not sure if you'll still looking or not. I have an old Promaster 100mm with the attachment gets a 1:1 on it you are welcome to try out if you'd like. I had it on sale here for a long time and it's probably still out there. It would be full manual on the 5000 but you are welcome to give it a try if you like.

Right now I have the Nikon 105mm VR, and also have the Tamron 90mm that is a great lens for almost half the cost of the 105 and you can usually find them out there for around $350 or so. Unfortunately I believ any of them would be full manual mode on the 5000 though, which is probably what you want to do regardless shooting macros.