Wordpress - Add Image Resizing To A Form

I am using a Genesis child theme and the latest version of Gravity Forms. I currently have a form setup using Gravity Forms. This allows 3 images to be uploaded by logged in users. A thumbnail of each image, e.g. image1, image2 or image3 is displayed if it has been uploaded, along with a delete button. If the image has not been uploaded a default image with a upload button is displayed. Each of the 3 images are identified using image names. Gravity Forms post submission filters are used to attach the uploaded images as attachments to a custom post that has been created by the logged in user. I am looking for a method to resize the images, ideally before they are uploaded. This will allow maximum dimensions to be set, e.g. 700px by 500px, as well as an overall file size limit, e.g. 500kb. I would like the resizing to work on as many browsers and devices as possible. I am flexible on how this is done. To me there are 2 options: 1) Add resize capability to the current Gravity Form file upload fields or 2) Use a separate file upload method and add the image resize function to that. This would need to be added to the current form with code adjusted to save the images as attachments, or the whole form could be replaced with a new form so that it looks and functions the same, with the addition of image resizing. If you have an alternative, better option then I am happy to consider it. I would note that I have tried using a plugin to do this but it did not work with my current setup. I can supply info on that plugin later. I am looking for someone who is experienced with Wordpress and ideally Gravity Forms and need to have this completed as quickly as possible. I would really value good communication throughout the project. For the right person it is very likely that I will have other work from time to time. To help stop automated bids please type "My bid is $x" at the start of your bid, replacing x with your bid amount. I look forward to hearing from you. If you have any questions please get in touch. Thanks Bob