I'd have to put in another vote for Montana Vintage Arms. J.C. and his crew put out a top-notch product. I own 3 full sets of his sights and will buy more if the need arises. When I had him modify a base for an unusual rifle, he happily did so and was willing to keep trying until what I had worked. The other offerings in their catalogue are superb products as well.
My take on some of the other suggestions.
Baldwin - same price as MVA, only seen one, but they look pretty good.
Jeff's Outfitters - Really low price. Until I see one, I'd say there HAS to be a reason. It MIGHT be worth the chance.
Shaver - Have never seen one, but they do have a following.
Pedersoli - Junk, heavy, clunky, not even worth the price of scrap.
Red River - The quality is hit and miss. Seen more lesser quality ones then higher quality. $100 cheaper then MVA, but lacking $300 in quality. Most of their users have buyers remorse.
Let us know how you make out.