Moda Marbles come in 210 colors, so I'm sure there is a red that you will find as perfect. I have a color card and can see at least four that I would call blood red...try cardinal 9881-12, brick red 9881-13, redwood 9880-57, or burgundy 9865 to start. They are all on the blue side of red. Both Hancock's of Paducah
http://www.hancocks-paducah.com/Item...Marbles--m-189
and Craft Connection
http://www.craftconn.com/Main.asp?Ta...CategoryId=110
have large selections of moda marbles and I have ordered from both with great satisfaction.
Craft Connection lists theirs in order by stock number which is very helpful, but Hancock's has slightly better prices on some specific mables. Craft Connection puts them all on sale sometimes in case you get addicted like I am. :D
On your border yardage, try the calculator using just the sizes of the rectangles you plan to cut, not the border function. Then add up those yardages for the total border.