you will need a nice big bag of patience if you want to work with Raw files over wireless. Transmission speed is too low and latency is just too high for that to work seamlessly. with that said Lets get started....
First: "secure wireless home network" How secure do you want to be? For the most Basic security, WPA2 works well just choose a nice password (15 letters min random, or a string of 5 or so words). That is bare minimum. If you feel like you want more security I would pass all the MAC address filtering or hiding your SSID as that wont work that just makes people interested in hacking into your network. Beefier security = WPA2 enterprise... Having a RADIUS server is a great way to to lock down any network but that will take more than basic hardware.
As for a network attached storage device If you like to go a little beyond the "in the box solution" I would suggest putting together a computer with a low powered embedded solution with an intel Celeron 1037U(An Intel Avoton processor would be great too!) with some ram, hard drive and the fixings.... This setup can have a huge potential with automated backups, Network sharing, Plex Media server (Awesome service) etc.... You can add drives as you need it, Possibilities are vast. I know the "in the box solutions can do this but can use proprietary formatting which can be problematic if the unit fails and you have a raid array, it will be hard to rebuild the raid if the whole thing dies and you cant find the same exact controller the raid was built on, all data is lost. Just something to think about
If you like to tinker a little and want to expand you knowledge about networks, data and servers This is a great way to get into it with plenty of room for growth.
If this is something you would be interesting in let me know and I can help.