A5 is fine.
You will be joining at Tamworth off the A51 from Rugeley?
M42 J 10 is tricky.
A clear fast run past Atherstone. I rode this section every morning and evening commuting from B4116 ( Merevale Lane ) to MIRA ( You'll see that ).
This section is FLAT. Flatter than Hartshill.
Are you planning the B4112 through Pailton?