The best bang for the buck in drones is the Phantom 3 Advanced. If you catch a good deal you can get one for $599-699. Add 3 batteries, the P3 multi-charger, a few memory cards, an Asus Zenpad 7 or 8, sunshield, & a case or backpack and you are all set for about the price of a base P4.
I don't know about the Executive Kit but $3000 is a lot of money. Whatever model you choose, I would order stock & see what sort of range you get before doing an antenna mod. My stock P3A & P4 can outfly the battery range in clean RF environments. No sense increasing antenna range if the battery is at its limit. If you discover you need more range in congested RF areas you can send off the controller for an antenna upgrade for ~$150. I would only add amps as a last resort because that really bugs up your controller portability & complexity.