Steve, while I admire your ingenuity, you've got to trench to the unit - you need to be able to secure the unit to the wall, run the conduit and BOND!!!! the unit - all of which is done on the back side of the pannel -sorry! . I suppose you could jack out a section of the deck to access the pannel, but a patch always shows.) (just be glad that you don't have 8' of deck there! ).
Sorry I couldn't make this a little easier for you, but it needs to be done right. If you have any more questions, I'll give you all the help/ info I can!