What size wire for 200 amp that is 280 foot away and what size ground. Also what size conduit for it?

Okay, first of all, is this a 200 amp load for a single family home or for some other use?

Just working with the raw measurements you gave us and assuming that you want 200 amps at the terminus end of the run and given the cost of copper I'm using Aluminum as my conductor. Also, I am doing my guesstimate using lateral (underground) connection.

You will need 3 ea. 500 kcmil THHW insulated conductors along with a #6 AWG bare copper equipment ground. You will also need Trade Size 4 Schedule 40 PCV conduit.

If you are attempting to feed a remote building from a main panelboard for an existing building all of the above would be true, but the grounding at the secondary building would be different.

Or you could consider having the power company put an overhead drop and transformer for you.

the more you tell us the better the answer...

Or underground and Transformer?