i think you got some good advice from craftsman on this bord.
I’m not an electrician but I am a carpenter and construction supervisor. the biggest mistake people make is to use bids from unknown contractors. I know we are told to get 3 bids and take the lowest one but you get what u pay for. if you don’t have the work you want done detailed out you can’t know for sure what the bidder is selling you as skilled installers, or if the materials are of the same quality as your higher bidders. Lots of the time a contractor will initially underbid and make up the difference in change orders and extras. a good bet is to ask around for the best elicitations in your area. make a detailed plain specifying all the materials (by make and model) to be used only invite recommended contractors to bid or even better if you find one stands head and shoulders above the rest give the job to him even if he is the highest bidder. ( if he is high it is probably because he is being honest )
Your job is a little small for this, but another good way you can go is to hire a “lead man” ( a lead man is a licensed supper who’s only role is to represent the owner in construction projects ) I have worked with lead man and can’t tell you how much easier and faster it is to address the unforeseen issues that arise if all parties are construction savvy.