I have been looking desperately for a Boswellia sancta tree. I have Theobromea cacao seedlings to trade for it.
Is it possible that you're looking for a Boswellia sacra (note spelling, please)?
I don't know how rare a Theobromea cacao is - in fact, I don't even know what it is, but you should be aware that what you're asking for is a fairly rare plant - even one in a 4" pot, if you find it, will likely sell for $30 (that was the price for the last one I saw).
If you're looking for that specific plant, I wish you luck and a large pocketbook. If you're looking for cuadiciform plants that have aromatic leaves, may I suggest the multitude of Bursera species that are widely available?
I have some seeds. The picture here is a new b. sacra germination. Very excited to see the seeds germinated.