I steered away from replacing my router with a PC and got an ER-X and virtualized everything else including TrueNAS on an old office PC. Having PCI-E slots helps with stability a ton when virtualizing and my setup has 64gb DDR3 which was cheap.
Ubiquiti APs are typically the homeLab standard and work great especially with multiple APs. You can start with turning your existing router to AP mode and replace with APs later.