Pomona is a major brand for test leads and probes (not for scope probes, though). They're now owned by Fluke. Most of the Fluke leads are also Pomona products. In Europe major brands are Hirschmann and HCK.
Any leads which don't use a fixed shroud on the banana plug should be fine. Unsheathed or with retractable sheath. Get whichever style you prefer. You'll probably want something with pointy tips to browse, and something like retractable hooks or alligator clips (I personally find alligator clips totally useless for most electronics work). Four wire leads tend to be expensive, you can also do a reasonable job by just using two sets of leads with some sort of clips attached, just clip two of them on each side (source on outside, sense on inside). Of course real four wire leads are more convenient.