tires

I searched the forums for 'tires' but couldn't find what I was looking for, so I am starting this new thread.  For reasons too tedious and embarrassing to explain, I need to replace the tires on my week-old 180.  Since my bucket list trip is scheduled to begin on 5/14, I need them fast. I am considering replacing my 205/75R/14 C-rated tires with D rated tires.  The only ones I can find online that are D rated in this size (none of my local dealers had any tire like this) are Kenda Karriers.  If I don't do this, I am thinking of Greenball Towmasters because my local Costco has them.  They are C-rated, however.  So my questions are:
1.  Can anyone educate me about the quality of Greenball or Kenda tires?
2.  Is it a good idea to replace with the D rated rather than the C rated tire?  (The cost difference between the Kenda and the Greenball is only $14.)
3.  Has anyone had experience with TrailerTiresandWheels.com in Edon, OH.  (They sell the Kenda tires for $148 for a pair.  Etrailer charges $199/pair.)

Thanks for reading this far!  Thanks for any counsel you can offer!  Thanks for helping me organize my thinking by writing this all down!

Maureen