RYTM with Overbridge.  Not a massive fan of layering, try to get the sound right initially when I can.  It does have its uses though, in awkward mixes.

Layering is easier if you start with a kick that is *almost* what you want. Then you bring in a layer to add a bit more sub-bass to it, and maybe another one to add a transient or click. I used to try to layer 5 kicks and make a frankenstein kick, but now that I treat it more like "find a good kick and then beef it up a little bit" it works way better.

I use a couple of the Freshly Squeezed Samples packs and some kicks from Splice sounds. I usually end up with a single kick and some careful processing lately, but I do layer sometimes.

I steal from the Adventure Machine
Boom, you have the best drums ever created

Do you have a file with what you've sampled?