It is based of Pixhawk2.1 flight controller. If you do go with a fixed wing like the Nimbus. You can buy a similar quad at foxtech for 700 its called the hover one. This allows me to use the same battery for both and can switch out my RTK receiver and expensive long range telemetry gear.

I'm currently running the nimbus and a folding 680 size quad frame. If you go with a fixed wing like the Nimbus I'd still suggest getting a rotor wing not a dji get something that is pixhawk compatible so you can share/swap parts. If you smaller projects it's really hard to beat a DJI Phantom I dont use them personally but you really cant beat the price. My favorite at this point is Foxtech's Nimbus Vtol it's a stupid easy bird to fly and since it does have VTOL capabilities it can be used to take off and land in tight areas. I'd suggest using Pix4D if you want to process in house and if you have larger projects that need flown a fixed wing would be best say 100acres+. Since your using topcon gear and ultimately Civil3D. I believe the biggest benefit to using TBC is that you can import a calibration/localization file from a data collector using Trimble software (access/scs900) and the software will automatically show you where the GCPs are roughly located rather than searching for them in other programs.

The photogrammetry module for TBC is also 7000USD not a cheap option if you're only looking to get deliverables into Civil3D. Unless something has recently changed TBC will only accept data from supported manufacturers like Delair so that would also limit what you can use hardware wise.

Holy cow you have a ton going on here! I'd say as a technical support person on the trimble construction side avoid the Delair bird at all cost! I've dealt with the UX5 and have not had the best experience with it.

Trimble business center support