Which extensions to use?

Hi,

I want to build a matching function where people can present themselves with their specialisms, and visitors can search based on their interest.
I expect that I can define the characteristics of the offered services with the custom fields in Meta Box, right?
Next thing is to allow the “sellers” to specify their specialities. Should I use the Front End Submission for this purpose, or better define each seller as user and use the User Profile extension? (I am trying to figure out to go for Core bundle + 1 additional extension, or gor for the developer bundel and have them all.)
Third thing is to enable searching through the sellers offerings. I understand that for this purpose it is best to purchase a license of FacetWP, right?

Would this all be a solid base for building such website?
Just seeking some sort of confirmation before purchasing any licenses.