Best bet is to come up the M40 the go M42 North and take the M6 northwest or M42 South and M5/M6 North West to the M54.

I wouldn't bother with the M6Toll it will take you way out of your way and then when you get to the other end you have to fuck about on A roads to get onto the M54 anyway. Plus on a Sunday you wont have any trouble with Traffic and there are no road works on the section you want to travel on at the mo.

The A roads you talk about are all fun interesting roads but if you get stuck behind somet it will piss you off.

Hope this helps.