Publish as undergraduate in Elsevier
I think that this will be good practical experience for you, regardless of whether you're proceeding to further study.

A few things to note:


Discuss your plan and involve your supervisor in your preparation of the manuscript. The reason for the first is that statistically significant results and a potential research gap aren't sufficient in and of themselves in guaranteeing acceptance. The reason for the second is because there's more to submission of a paper than simply writing it. Your supervisor will be able to provide you with guidance.
Read and dissect some papers from the journal to which you plan to submit. This will orient you about the style of writing, formatting, referencing, etc. Certainly, read the instructions to authors, but also be guided by good samples from the same journal.
Prepare emotionally for the review process and the decision. First time authors are often surprised by the delays, unhelpfulness or viciousness inherent in the peer review system. 


Good luck to you.