I personally thing it should be more simplified. An electric version of the RailCraft tunnelbore that moves a great deal faster and runs on EU.
Recipe: Regular Railcraft Tunnel Bore in the middle. Followed by a diamond drill head, also from Railcraft to the left of it. Then, somewhere on the top row, there should be 1 energy flow circuit and 1 data control circuit, and 1 mfsu.
Reasons: It makes sense that a diamond drill head and a railcraft tunnelbore be parts of such a high tier mining device. The energy flow circuit manages the EU usage, making sure not to burn out the motor. The data control circuit makes sure that the system has its needed energy and manages placing ballast to make bridges. The MFSU doesn't allow the Electric Tunnel Bore to hold any EU, instead it is used for its ability to draw power from Batteries & Crystals.
Design: 1 slot for inserting Energy Storage devices into. 1 slot that depleted Energy Storage devices are put into. Then 9 slots for ballast, and 9 slots for rail, much like the original tunnelbore. Also like the original tunnelbore, you will have to use chestcarts to store the output.
Edit: It would be HAYO levels of awesome if you could also add 9 slots for torchs which get placed every 9 blocks or so, adding yet another level of automation over the original tunnelbore.