the Surly racks will certainly fit an LHT and are probably completely bomb-proof, however, they are much heavier than the alternatives. They're sort of expedition-class stuff that is truly excessive for normal commuting or light/medium touring.
For commuting only, take a look at the Axiom racks. . .very affordable, seem very well constructed. I don't have direct experience yet but recently installed the Streamliner Sport Tour on my LHT and expect it's going to suit my needs fine. It's not designed for a trunk pack so it may not meet your needs. Their other products seem equally well made, but again, I don't have direct experience and can't speak to their durability yet.