I think the best and easiest way for you to get in touch with the nem devs and actually quite a few devs working on/with nem is to join the telegram/slack channels.
If you can tell us a little more about your project we might be able to give you some pointers right away though.
Generally speaking it is an awful idea to put big chunks of data on the blockchain. Using the blockchain to make sure data are consistent is one thing, but actually puting all the data on the chain is, unless they are very small amounts, a really bad idea. This goes for any chain, not just for nem. If you want that in a decentralized way you may wanna look into IPFS and the likes.
Tell us a little more if you can and if not join the slack/telegram channels and you’ll be helped