We can't ship the first book first, but I can certainly send you a PDF version to use! Email me at FelixIsaacs@thewildsea.co.uk with proof of pre-order (or something similar) and I'll make sure you get a PDF ASAP. :)
Actually I just bought the bundle and gave me the PDFs for both the core book as well as SAR. Thank you very much though. I can't wait to get my hands on physical copies come April.