can you sell listing by zip and category?

my website is notarybyzip.com I also have an option for the user to search for notaries that work different hours, go to different locations, and notarize different types of documents. ( I only have one category, I have each of these options setup with multiselect custom fields)

As I was thinking about what price packages to setup, I am wondering if I can sell a notary in 70605 zip code that does vehicle titles to show up on the top of the search results as one payment type.

then a notary (maybe the same notary) that is in the same 70605 zip code and does Power of Attorney Documents as another payment type or fee…

so each notary could choose what “document type” they want to pay to be top in the search results”

also am i able to setup to “sell” the TOP listing and then also to sell a “2nd-5th place listing” and a “6th-10th place” listing ? or do i have to sell them in number 1 placement, number 2 placement, number 3 placement, number 4 placement and so on.. thx

another question… i do not understand in the “prices and payments” what the “post field” option is for… i have read the instructions, but I just don’t get it.