if i added a citys field for example to my form is it possible to have

Question, If i added a citys field for example to my form is it possible to have a second form replacing the wp default search with a gravity form that will search say title,body, categories keywords and
a drop down for the city so the form will only return those results from that city/categories ecs that are chosen ? there are many category examples in wp codex but non will work for me using this form. please see testing domain http://nichedeliverysystem.com/ click “ post new ad “ as if your a poster to see form. I know that i can enable values and manually add the citys for the states in this drop down ( setting up sub domains/ directories in cpanel for each state fyi ) so the user experience should be as follows

they go to http://nichedeliverysystem.com/ there will be a list of states.

they choose there state example newjersey. the domain.com then search choosing “ all or city,topic,category ecs.”

basically i would like to add too or replace the current search tool we use with a gf if possible?

I need a way to sort entries, the search works great but does it support the AND clause? I need to search like "123 AND company XX" so it can sort the collums but 123 with in the entries that have a company called XX, get it?

The back end... also while I have your attention, Is there a way to add "create an entry" directly from the backend? This is so the admin can add an entry for someone else...