Lighting - Can go with Control4 and have plenty of options. If construction isn't that far along I'd look at their Centralized lighting option. This eliminates all of the wall clutter and simplifies your electrical plan and troubleshooting. If not hiding as many loads as possible and using programmable keypads is a good alternative.
Controller - agree with SA C4 - EA5 all the way on this. It's robust and will handle your system as you scale.
Remotes/Interface - I like the NEEO's (have 6 in the house) and have 2 SR250's. The 250's have gone in the drawer now that the network here is more stable and upgraded. They operate off the wifi so be sure your network is robust. Mine will occasionally lock up briefly and just is a quick 30 second restart of the device
Multi-Zone Audio - Recommend Triad Audio Matrix. Have had unit installed along with three 8-zone Triad Amps and works great. They do run a bit hot so your integrator may want to install AC Infinity fans between them in the rack.
Video - Would recommend looking at AVPro Edge 4k Matrix instead of C4. More robust and reliable in my experience. Currently have a C4 4K Matrix and at least one channel cuts out semi-regularly. Ended up installing OVRc enabled Wattboxes and programmed reset to handle this. Would recommend a Wattbox and OvrC devices to plug in for remote reset of devices anyhow (i.e. ,modem, router, switches, audio matrix, video matrix, cameras, etc). Huge time and money saver from service calls and the associated expense.
Security - Like the DS2 door station from C4 (2N is the actual OEM). Integrates into phone via Intercom Anywhere app and touchscreens if you install thru the home. For locks as long as they are C4 compatible you're good to go. Have Yale Locks with touchscreen on both gates and Baldwin locks for all doors to the home. The Baldwin have been installed for 7 years with no issues. The Yale Locks for just over a year with no issue. They get exposed to extreme heat here (Vegas - 115 degrees) and the occasional rain storms with no issues.
Climate - Would have to agree with others on the Control4 thermostats (OEM Aprilaire). I have Nest units integrated and worked fine until Google migrated everything over in the last few months. It still works but has been a pain.
Network - Wire to everywhere you think you may need even if it's just a wish and not a 'today' project. Can attest to doing this on my home as a retrofit and would have been far less expensive if just did all the runs to everywhere imaginable upfront than doing so after the fact.
Enjoy the project!
Last there is a video on YouTube that's quite long but informative worth watching in small bits: