Alright, first the difference between hub and lug centric...
Lug centric spacers are centered by the torque on the lugs while hub centric spacers are centered on the center bore of the wheel. Which one is better? I would say a "good" hub centric spacer is going to be better because the load on the hub is balanced on the center hub rather than on the actual lugs. The problem with lug centric is that as the wheels turn the torque shifts, and so something that is lug centric will actually move while it's in motion. Most aftermarket wheels are like this too, not just spacers. The problem is when you combine after market lug centric wheels with lug centric spacers you now have a torque shift taking place on top of a torque shift which can equate to some serious vibration.
Hub centric that fits the center bore properly will fit snugly on the hub ring and not allow any movement. This is better for the wear on components, but the problem is different cars have different sized hub rings. Stock wheels are designed to fit these hub rings fine, but how do you know if your spacers or aftermarket wheels are going to fit the hub ring the same way?
Really they don't... They're all designed to basically fit the largest hub ring so they can be "one size fits all" so to say. Now some companies do make hub rings specifically to fill in the gap between the hub ring on your car and the bore space of the hub/wheel, and that's probably the closest you're going to get without being really lucky.
When I installed spacers on my 240SX my big concern was strength and rigidity. I didn't want spacers that were going to be a cheap alloy and crack or break under stress. I went with H&M because their magnesium allow spacers looked to have the highest strength to weight ratio of the ones available for my car at the time.
Good luck finding the ones you want!