First of all, sweet deal on the LED's!
As for a neat plug, just go to a hardware store, Home Depot, etc. and get a good quality plug, style per your prefence. You can make it look nice/clean by buying some 'zip cord' which is like lamp cord, and connect to the black and white wires on one end and to the plug on the other. You could cut off some of the black/white copper if you want to to clean it up. You can also just use wire nuts to connect the wiring which will be easy, or if you are handy I personally prefer in-line solder connections which are then double shrink-wrapped-JMHO
As for the dimmer, I would go look up this lamp on-line. I can see that it's made by Osram. Just Google 'Osram model# xxxx' and see if you can find a wiring diagram and /or technical reference.
FWIW-These type of dimmers usually work off of a 0-10 VDC signal, or in industrial applications a 4-20 mA DC signal. The way to make these work exceeds a thread IMO. Best bet is to find the wiring diagram/tech reference. If you are in doubt about the dimmer function, find someone near to you that is good with electronics, because you can fry these if not careful.
Good luck, and remember to post some pictures!