What suggestions are there to make a 2007 Honda VT750DC better fitting for a tall rider?  

I don't know if my reply came through, so I'll post it again.
I have a Honda VT 750 DC also.
I tried a 6" extension kit on the shifter and brake controls. It was too much for me so I keep the stock set up. I would let the kit go for a reasonable price if you are ins tread in it.
How Tall are you??  

I would start with a forward control kit to relocate the foot controls.  I installed one of these kits on my 2005 Shadow Aero and it makes a big difference even though it only moved the controls by a few inches.  I also upgraded my foot pegs.  Keep in mind this might not be possible if you have engine guards mounted to your foot pegs.  Next, I would look at handlebar risers if you think they might improve your riding position.  Lastly, I would consider a custom seat to give you a little more leg room.