Reputation system: weighted points vs unweighted points?

I am developing one small reputation system, and I faced one problem.

So, in my example I want to create a website for pictures with 4 different types of user; let's call them: amateur, good, very good, professional.

Each user can upload a picture and this picture can get rated by other users. When the user reaches certain number of points, he passes to the next level (e.g. if he was amateur, he becames good).

Now my question is: How should I develop this reputation system?

Should I include weighted points or unweighted?

E.g. if professional user gives 5 stars to a amateur user pic, should this bring more points then when a good user gives 5 stars to an amateur user pic? Also for negative points.

Which path should I choose? How to choose the right solution?

Is there some name for this kind of "problems" so I can read about it?

Could you address me on what should I pay attention with both solutions and what are the pro and cons?

Thank you

PREVIOUSLY READ: I read about SO pointing system, precisely this:

http://meta.stackexchange.com/questions/57278/if-a-user-has-good-rep-on-a-particular-tag-shouldnt-his-votes-on-that-tag-weig

This answer made me think about. Which way should I choose?