Normally you want your interconnection ports to be faster than your access ports to avoid one user filling the network. So if you have 1G access ports you most likely want 10 gigabit inter switch interconnects with a 10G core switch.
Unfortunately there are two different common types of ports used for 10G and the two cannot easily be connected to each other. The types are SFP+ and 10GBASE-T.
SFP+ was designed as a slot for fiber transceivers but for short links it is also possible to directly connect two SFP+ slots with a direct attach cable. There are two relevant types of SFP+ transceivers for a single-site greenfield deployment, SR and LR. Both operate over a pair of fibers.
SR is for multimode. On good quality multimode cable it should be good for 400m on OM4 (less on lower grades). The downside of multimode is it tends not to be very future proof. Each increase in speed results in a significant reduction in operating distance for a given fiber type.
LR is for single mode fiber. It's good for 10km and single mode fiber. Single mode fiber tends to be far more future proof than multimode. Downside is that the installation tolerances are less forgiving and the transcievers are more expensive.
10GBASE-T is a physical layer for twisted pair copper (ideally cat6a but for shorter runs cat6 should also work). Twisted pair is a lot cheaper than transcievers and fiber or SFP+ direct attach cables. Downside is it's relatively power hungry, the range is relatively limited, there is less choice of devices, the 10GBase-T versions of devices are often more expensive than the SFP+ versions and it will likely leave no headroom for upgrading to faster speeds on the same cabling later.
AIUI the big names like to make you pay through the nose for 10G. Some of them also try to bully you into buying their overpriced transcievers. AIUI if you want economical 10G gear Netgear are apparently a good choice.
With some switches it is possible to aggregate ports but it's less than ideal, especially if the number of data streams is small. I would push for 10G over aggregated 1G even if it costs a bit more.