jQuery/PHP drag & drop image upload/resize script

I'm looking to hire someone to build a new version of an image upload/ resize script for my admin area. I currently have one in place which is about 5 years old and now in need of a refresh. I run a high volume used car dealership and on average add about 5 vehicles into our inventory per day, with 10 - 20 pictures per vehicle. My current script is very very slow, and requires to much user input. I want the script to start once the pictures are dragged into the "area" (page, div, span, however it is coded) and save the proper order of the images when I drag them around. My current script wont start until I click start, throws a lot of errors, and wont save the proper order untill I hit save. I know that these might seem like small things to complain about but when I'm multi tasking and doing my usual 5 things at once and forget to hit "save" after dragging 20 images I get mad. I want to drag the photos and have them resized 3 times, (thumbnail, medium and large,) place them into the corresponding folder, and save the proper order of the image sequence in my dB. (My current script does do all of this, but like I said, it is very slow, and throws a ton of errors.) Facebook, Google Photos (and a ton of others) have good examples of what I'm looking for. The most important thing is that my current script must remain usable until the new one is complete. If your work is good I have some other things that I could possible have your help working on.