I would suggest a custom wheel build. There's no doubt in my mind that what you need is a Tiagra hub. 130mm spacing and very high quality at an affordable price. As for the spokes, DT, Wheelsmith, or any other spokes from a good brand - 36 of them, laced cross-3. Straight 14g stainless spokes will serve you well and are affordable. As for the cassette, you can run a 7-speed cassette on those hubs by using an extra 4.5mm spacer (or an old 11T cog).
Remains the rim - lots of good choices here. You want a quality double-wall alu rim. What rim you wants depends on the tire width you like to use, among other things. Sun Rhyno Lite for wide tires, or a Sun CR-18, or a Mavic XM317.... Certainly can't go wrong with those, but you have a lot of choices.
To finish with a Sheldon quote...
"In my opinion Tiagra hubs are superior to all non Shimano hubs except Phil Wood. Shimano hubs are unequalled. Sheldon "Hubs" Brown"