Oncology nursing student...peds or adults?

I am a senior nursing student and in the next few weeks we'll be putting in our requests for our final semester practicum. We'll have a preceptor and work 180 hours with our preceptor in a particular nursing specialty. I'm having a really hard time figuring out how to rank my choices, and was hoping you all might be able to help.

My heart is in oncology nursing. I know that for a fact. I am pretty sure I'd like to focus even further on pediatric oncology, but there is no practicum available that focuses on such specialized peds nursing. I would rather do adult oncology nursing than peds nursing in general, and I am pretty sure I could get a practicum on an adult oncology floor.

So here's my dilemma... Would it be better to get oncology experience with patients of any age and then seek out work with the kiddos later, OR would it be better to get pediatric experience and then specialize later? Is it possible to be hired onto a peds hem/onc unit if my oncology hours have all been with adults?

Any suggestions from those of you who are already in the field? I'd appreciate any insight! Thanks in advance.