POS System Electrics
Confirm with an electrician that your electrical layout can handle your POS computer system. It's unwise to cut corners over this issue. You need a consistently reliable electricity supply because every feature of your POS system is on a network similar to those used for office computers.
Circuit overloads may blow fuses, and other electrical devices may cause power fluctuations. Both of these can seriously disrupt a POS system.
An electrician will probably recommend installing a separate electrical circuit that serves your POS system and nothing else.
The heart of your POS system is a computer. You can buy this separately but it must match the POS system supplier's specifications exactly. Most people, however, let the supplier install a computer along with the POS system. This way, the supplier has responsibility for setting up the entire system and can provide a guarantee and further support on that basis.
In any event, although the POS computer is crucial to the success of the POS system, it will only be a low to mid range model and therefore relatively inexpensive.
POS System Compatibility
You may, however, want a POS system with software that can run on any PC and that can work with different types of POS hardware. This type of flexibility is best suited to more straightforward POS systems. Software designed for particular retail or hospitality needs will run far better with the hardware that it's originally programmed to match.