The standard naming convention doesn't change, so all buyables are cross compatible.. If Vacation won't let you buy certain clothing items, such as lingerie and swimwear, you can always download a free program like SimWardrobe or buy one like SimEnhancer 3D that'll let you make modifications to your Sims default clothing (such as lingerie and swimwear) outside of the game..
SimWardrobe can be found:
SimEnhancer 3D can be found:
Both of those should work, but to tell you the truth, I've had all of the EPs installed for so long that I don't remember if they work right without Hot Date..