I searched this morning for a low profile bolt to replace the oil drain plug. Basically, its nothign more than a 12mm x1.5 (fine thread) metric bolt. I imagine something 10-15mm long woudl be ok. Sadly, nothing is commonly available. A few guys sold some on the forums, but thats been several years ago.
One option was a bolt from Navistar that fit a fuel rail. No idea on a part number. The other option was from NAPA. The part number was BK 7041384. The cost is low..or was. I'll try to find oen of these tomorrow and see what they look like.
Once a low profile bolt is in place, the guard itself can be trimmed and free up some badly needed clearance. I also priced the new style oil pan from Service Honda (Service Kawasaki) and the total price, with gaskets, is under 200.00. Probably right at 200 with shipping. I'll probably go this route as soon as I get an ass-full of searching for a non-existent bolt.