KDP Print will give you a free ISBN for your paperback. In any case, I think it is much easier to produce the ebook first. I normally produce my ebook in Word format, get it edited, do all the proofing runs, and publish it. Also- during the ebook publishing process, you can download the MOBI file (KDP) and email it to a reader device prior to publishing. I find that is the best way to proofread the book.

I then make a copy of the Word file, and reformat it for print- page size, margins, gutters, odd/even headers, etc... then make a PDF. I use KDP Print but it is similar to Createspace.