What you have so far is how my Shrike is armed.
For the rear turret, you might think about missile defense and I have found the PRG and the PBE really good at this job.
Mixing CIG's and ISR up front is something I do with pretty good success.
Many of my M6's and M7's are set up this way.
I found enough IBL's for my Shrike so I have those up front on her.
Keep looking, I'm sure you will find them then you can change your weapons load-out!
EBC's are hard to find in my game.
I have plans to built a Complex for those and FAA's, also in limited number in my game.
I found EBC's great as anti-fighter defense---those few that I have.
I've placed them on a few of my freighters. Finding ammo is also an issue for me.
It's not what someone has done..it's about what they are about to do!