@sam_uk - had a closer look at the documentation http://navspark.mybigcommerce.com/content/NavSpark-User-Guide_rev0.8.pdf
I'm not sure the Navspark mini (17mmx17mm model) has enough pins for the job - I may be wrong but I couldn't find where you'd wire in the NSS pin. Perhaps someone with a better grip on this stuff could advise?
The Navspark (non-mini) looks capable enough through.