Minimum quality of tap is Hansen or Vermin America brand, I only use them 'cause I can get them on Sunday afternoon at the local hardware store. Anything better and/or non-standard, I have to wait for the brown buggy to deliver. Home Despot/Lowes/HF carry peculiarly ridged objects that they're pleased to sell as taps. Good taps can be had at fairly decent prices from the likes of MSC, better prices in quantity.
On aluminum, I back up every 1/4 or 1/2 turn to break the chips with straight fluted taps and use a proper cutting compound, Tap Magic is one brand I've used, Alumi-Cut is another. Extruded aluminum is gummy and will build up on your tap without it, you can get things so plugged that it will jam and you can't get it backed out without breaking it. Those small holes can be buggers to do sometimes, a tapping jig using a bushing can help a lot. I also like using a dogbone-type of wrench rather than a T-handle, there's less leverage there and I can get a little better control and less side pressure. I like a little Starrett unit I bought long ago for taps of that size, it's about 2 1/2" long. 2-flute taps are good, too, they've got a little more rigidity in those small sizes.
10-32 may be a bit too fine for extruded aluminum unless the extrusions have been hardened. You might find that when you torque your fasteners down that the holes will strip with fine threads in soft material. Without knowing more about your project and the load you want to apply, it's hard to say what you need. I'll repeat the old saw about needing at least 3 threads in the material to hold well.Another alternative to get a small threaded hole is the threaded insert or nutsert, there's a number of different types of these, some are available in stainless or aluminum.
Stan