I have some 1-pounders that I bought at Target years ago (I don't think they sell them anymore), and an alternate pair of one-pounders that I just bought at the nearest Reebok factory outlet. Both are Ironwear gloves, which I have found to the be most comfortable. I've tried styles that contain sand (they shift and feel like they put some torque on the wrist), styles that have the weight on the back of the hand (they felt unbalanced to me, and also seemed like they put torque on the wrists...but I've got really small wrists, so that may be why), and the harder ones at Walmart (they rubbed against my hands and would have caused blisters if I kept using them), but Ironwear are the most comfortable ones I've found.
I also have a 2-pound and a 3-pound pair that I bought off the internet (I searched "ironwear gloves" or "weighted gloves": they are both Ironwear) that I use for AWT like the Firm or other workouts where you hold light weights, or for doing moves like birddogs with light weights, but they are too heavy,IMO, to use for kickboxing, at least for an entire workout. Just to be on the safe side!