I, for one, am not sure I understand the question. I would run the coax in plastic pipe, 1 inch black irrigation pipe at the least (need NOT be NSF). One or one & a quarter inch NMT (plastic conduit) is more rodent proof and probably adequate for most needs. If you are planning on more dishes, C-band with acuator, etc. you might even want a bigger pipe. And since this is the C-Band forum that is likely! Personally, I would not bury metal pipe except to sleeve plastic pipe where it might be driven over.
For the exact type of RG6, I have found not definative reason for using the quad, however, I noticed prices today and quad was only about $20 more than regular RG6 for the 500 foot roll. Therefore, when I buy my next roll, I MAY get the quad. I have not checked the price on EBay but the regular RG6 at my local HomeDepot was $47. for 500 feet.