That was my initial thinking as well until I saw the 10-port requirement.
2 APs and 8 wired clients.
Unless at least 3 wired clients are in the same subnet and can be connected using a simple switch ?
SFP to GbE is no problem:
S-RJ01 for up to 1Gb
S+RJ10 for up to 10Gb
If you consider the POE version of RB5009, it will “just” be insufficient for powering cAP AC (depends on the load), probably not strong enough for cAP AX (it has higher power requirements) since RB5009Pr can only provide 20.16W on a single port when using 48V power brick (cAP AC goes to 24W, cAP AX goes to 28W).
Also:
for 2 APs, don’t bother with a controller. Set them up manually, much easier unless you REALLY want to learn !
In the latter case, be aware you can not mix wifiwave2 device with legacy wifi devices (so 2x cAP AX, or 2x cAP AC, no mix or forget about the controller).