Hey

Currently it is paypal, although i'm sure we could work out something else. I'm the one who takes care of the prize funds, so if you'd like, send me a PM with payment options available to you and we can see what we can work out.
As far as the contests - I'm not sure which ones you've viewed, but normally there's on average around 10 different designers participating in any given contest. You'll see that some designers specialize in either logos, illustrations, web designs, etc - and of course there's some that excel in more than one area. We have had a couple of contests lately that have only been open for a couple of days, thus not allowing enough time for more to participate.
As far as working directly with the designers, that's completely up to you. All that we ask is that if you do host a contest with us, please refrain from contacting any of the designers privately in regards to the contest until it's over. Once your contest is closed, you can coantact whomever you'd like. Any arrangements that you make directly with any of the designers are completely between the two of you, including all terms and payment agreements.