So here are a few thoughts...
1. mediaADNET, but like you said, maybe some players don't have latest version, but this would be ideal, easy and packed with features
2. Pepper API, do anything you want automatically via our open source API, but does require some JavaScript skills
3. Use the collection component, so you don't need to worry about sizing, as it is just a list, but opt #1 and #2 are more powerful
4. Use common channel to share content, but again will only help like in #3 if sharing a campaign within a single account
5. Possible having single timeline with multiple outputs, each output can be assigned to a different station so the timeline is now a shared module, again within a single campaign.
my choice #1 or #2... if possible
regards