Roadtrip from Denver to Mt. Rushmore/Devils Tower and back

[yoshitoshi]

Hey everybody,
I'm planning a 5 day road trip on april 5, landing in Denver from LA,
I'll be happy to get some tips and suggestions from you about attractions, best routes and more...
The plan is to stay one night in Denver, and then drive north to boulder, cross to SD: rapid city, Mt. Rushmore, badlands, and then jump to Devil's tower and back all the way,
I want to know if there's a good circular route so we can get the most out of this short trip,

*update*
after reading a little bit, I came up with this route:
Denver to Kimball to Scotts Bluff National Monument, passing Agate Fossil Beds National Monument and Oglala National Grassland
then heading to SD to black hills, mt. rushmore and badlands
passing to Wyoming for Devil's tower and then heading back all the way to Denver (maybe stop in boulder)
so my question now is Where can i plan to spend a night in...
and is a good plan??

thank you for your help!