Thank you note to CNO/HR manager/Unit director

Hello! I really need some advice and help with wording a thank you note to the leaders of the hospital I have worked at as a CNA.
I graduate NS in May and the CNO, HR director, and Med/Surg unit director all encouraged me to shadow the experienced nurses. I did this for six 8 hour days. I learned a ton, everyone was so kind to me.. and I really really appreciated the opprotunity. No job has been offerred officially even tho they have talked with me about working as a nurse..but I wanted to thank them and maybe remind them that I will soon be an RN (take nclex in 4 days!!)

so far I have for the CNO (it's a small hospital and she has a strong hand in the hirings):
"Thank you for the opprotunity to shadow the experienced nurses on Med/Surg. I am very eager to work as a RN and look forward to talking with you more about establishing my position with ____ Hospital."
To me, it doesn't sound right... Do I also write a separate note to the unit director? Is this a good idea to even send a note?? Any suggestions?
It is a good idea, especially with the economic climate. I did something simiar, but via email. I don't remember what I wrote, but it was brief and to the point (they don't have time for long letters). What you have is good, but this is another suggestion.Dear XYZ,I appreciate the opportunity given to me to shadow the nurses on your unit (or name of unit). It was an exceptional experience, and it highlighted/confirmed/renforced my decision to work as a RN in xyz unit. I learned a lot from the nurses and other members of the interdisciplinary team. One case in point, was when blah blah blah (give an example of something you learned). I will be graduating on xyz with BSN/ADN/MSN, and plan on taking the NCLEX on xyz. I believe xyz hospital would be a right fit for me, as I begin my journey as a RN, and look forward to working with xyz unit and the staff. Again, thank you for this great opportunity.

The note is a great idea, especially because they allowed you to do something that CNAs don't normally do."I am very eager to work as a RN and look forward to talking with you more about establishing my position with ____ Hospital."