For tapping and general work, I would suggest you buy wire size (#1-60) first, then fractional, then letter size drills. While more expensive than jobber drills, screw machine drills are stiffer and tend to be more accurate. As for brands, there are many. To name a few, Precision Twist Drill, Chicago Latrobe, Cleveland, Triumph, Titex, Guhring, Dormer are all very good. Makita produced a 1/16" to 3/8" set that is amongst the best I've ever seen, and I've used a lot of drills in my time. I haven't seen them for sale for a very long time, though.
Best bet - cruise ebay and watch for sets at a fair price. Any set from the above list will serve you well.