I know I posted an 808 sample pack somewhere around here... Trap is honestly entirely based around the 808 and 909 drum machines.
Try time stretching or pitch shifting a basic 808 kick, that'll get you that nice low, boomy kick. For the Hi Hats try using delay units and colouring the delayed sound a bit, or using the same hat twice with some different filtering and such. Ie, have a hat playing every 2 16th notes and then a delay set to 1 16th note with a small amount of feedback.
For the snares and toms just throw them into a sampler and then mess with different notes.
What exactly are you looking for?