The questions you are asking suggest that you aren't quite ready for this opportunity yet.

For 175 people, with full prep done earlier, day of you are looking at 3-4 people in the kitchen, depending on the entire menu, and about 10 people out front to set up, serve, and clean up the party. $18 to $30 per hour.

pork tenderloin

herb crusted chicken

I would get chicken breast cutlets such that 2 made one serving , about 3 ounces, and count on 1 per person. Then for the tenderloin, assuming it is being sliced and served at the serving tables, start with 1 pound raw boneless per 3 people.

Just to reiterate:
it is ALWAYS the caterer's fault if you run out of food; it doesn't matter if they didn't order enough; part of your job as a pro is not to accept a job where they are not willing to order enough food, because the fastest way to RUIN your rep as a caterer is to run out of food at a major event, and a wedding reception is the most major of major events.

If you are responsible for setting up serving and cleaning up, you need at least 10 people (at $100 or more per person) to serve this large a crowd.

In most states it is illegal for you to serve food for sale unless it is prepared in a licensed kitchen or the kitchen of the host.

Also, you need event insurance, as you are legally liable for any sickness or injury to guests or staff, even if it is "not your fault". You need at least single event liability insurance; you can be sued (lose your house, etc.) if someone is injured cooking or serving or eating the food.

The contract you have with the client specifies how many people you are paid for, cost to client per extra person, and who gets the leftovers. Most caterers nowadays, do NOT give the leftover food to the client, due to liability issues. What equipment and supplies you are responsible for , all the way down to napkins and plates. Payment of 1/2 at the time of the contract, the other half day of, before you leave the site. Cost of cancellation and how late they can cancel or add guests. What set up and clean up supplies (do you bring the garbage cans and haul away the trash?) and lots more. You do have a contract, right?