Cisco Seamless WiFi?

Question

WiFi

Task: deploy seamless wifi for ~150 clients, office ~100x50m. Budget - 150k.
The Cisco 2500 Series was chosen as the controller, due to the lack of price analogues from Cisco, it remains a constant. As access points, I look at the Cisco AIR-CAP3502E in the number of three pieces.
I would like:
1. 600 mb / s (if 300, then, well, ok).
2. Good roaming between points so that Skype calls are not hung up.
3. Reliable connection to the network, provided that 50 people connected to the point.
I ask for advice from those who have implemented similar tasks.
ps Not necessarily Cisco, the forums say that they are the most reliable, so the choice fell on them. (Do not offer UniFi)
pss Points must be powered by POE

Answer 1

A bunch of options: Aruba, Meraki, Fortinet, Ruckus, Aerohive
Compared to them, Cisco is expensive and inconvenient to manage. Further, questions:
1) where did 3 AP come from? The limit of simultaneous channels, as I remember, is 24 per point. And it's best not to be at 75% load, so think about 6-7 points for fast and reliable coverage, especially if you want 300-600mb/s. Do not forget that the point has 1-2 uplinks of 1Gbit each, which is also divided into clients
2) What Wi-Fi planning tool was used?