Kirk, I had my local guy put an insert into the head when I blew a plug. IIRC, he only charged me $200 or so. But I'm sure other places charge more than that. He also did it with the 4.6 kit, though I know he had to rig it to use it.
I suppose it would also depend on which cylinder. Mine was cylinder 7 (driver's side, 3rd one back) and it was a straight shot in to access it. Maybe find out which cylinder blew.
New bumpers are a couple hundred bucks plus paint. At 140K, it's only a matter of a little time before the cooling system plastic parts/hoses need to be replaced. IIRC, that is in the $700ish range.