I have a few points to make about your competition:
I have had some experience with running a level design competition (since I ran the closest thing to an "official" level design competition on the forums for a good part of last year) so here are my observations:
1.You are not organized.Not a good thing.You don't have any guidelines,rules,deadline,definitive prize list or anything like that.
You have to spell everything out and have all of the details worked out before you start something like this.
The very first level design competition we had featured only stock media or free media that you could download from the FPSC forums or you could make your own as long as you gave it away on the forums.It blew.We had one good entry,one that sucked and some rube sent us an .fpm file and he got a prize just because he tried.
That was all of the entries we got.
And just wait...four seconds after the deadline you will get your first "who won?" post...
Your best bet is to think this over and get organized and look at the way some of the other competitions are run...there is one for making models in the models and media forum and one in the 3D Chat forum as well...that will give you some idea of what to do and not do.
And I am sure Eureka can jump in and give you all sorts of pointers as well...and he will back all this up...he had a few "minor disturbances" with his contest.
I am not saying you shouldn't have the competition.I am just saying that the presentation so far is not impressive.And unless the forum members know you really well (Keith and I did it for the longest time and those that took over had earned their stripes) most people aren't going to trust you with their media.
I am not trying to discourage you or come of as a/an [insert your own insult here].I am trying to prepare you for what is coming.
This is a lot of responsibility and a pain at times and I am trying to save you a lot of aggravation.
Please have mercy and use the search function.