The downtube shifters bosses come with the Ergo and STI kits, I suspect barcons too. I've bought them before for like 10-15 bucks for the shimano ones when I landed some sora brifters for my kids bike. As for the wheel, are you using a road wheel? The LHT has 135mm spacing which requires an MTB hub. I'm using an XT rear laced to a 700c CR18 on mine. Like here:
www.wolfenet.org/gallery/surly/img_1543