that's pretty advanced and it doesn't sound like you are all that comfortable w/ WP yet, no offense. you can definitely do this w/ alchemy (i have and do), but you really have to get down and dirty w/ some javascript to 1. launch the media uploader and 2. to hijack the send to editor function.
some good reads: http://austinpassy.com/snippets/wordpress/creating-custom-metaboxes-and-the-built-in-uploader/ http://www.krishnakantsharma.com/2012/01/image-uploads-on-wordpress-admin-screens-using-jquery-and-new-plupload/
as far as alternatives: you might want to try the the Metabox class by Rilwis.
http://www.deluxeblogtips.com/meta-box
or advanced custom fields http://www.advancedcustomfields.com/
both are much less DIY than alchemy. pretty sure the one my Rilwis even has the plupload drag and drop uploading and a simple way to turn on repeating fields.