Ad-Hoc Mobile Banner Resizing

We are expanding our business and looking for new talented fast designers to work with for the long run. Our initial requirements are re-sizing and re-matching existing banners to many sizes. Usually work will consist of an existing set of banners (usually 120X20, 168X28, 216X36, 300X50). Sizes needed will include, most cases, 300X100, 300X250, 428X70 etc. The emphasis is on enlarging the banners proportionally and not simply using a regular primitive resize option in PS... If necessary some creative work might be in order. Please note that this is a Ad-Hoc based for a start, so everytime we need to get the work done we'll send it over to you, so the pricing should be by the hour, we're expecting 1-2 hours daily for a start. Once we're up and running, you'll have plenty of work for us, as we run dozens of campaigns and hundreds of creatives.