I am currently modding an old Aussie Charcoal grill to sear steaks. I am going to use Lump and/or wood for the heat source and had a few questions. Note the position of the intake holes, there are 4 in the rear and 4 in the front. Should I have the holes below the heat source, if so I will have to drill out more holes lower and place the fire grate above the new holes. If I use the current holes the Fire Grate will be too high if the holes need to be below the fire grate. I ordered a Porcelain Coated Cast Iron rack for the cooking surface and want that at least 4" above the coals. Should I add another heavier plate for the bottom or is the one shown in the picture ok?