we've got tons and tons of hours of skype calls and whatsapp convos. And a million pictures together by now. LOL! I hope that's good enough! 
You only need 2 photos maximum - I would go with one near the beginning of your relationship and one from the wedding.
You don't want to send more than 2 pages of Skype call logs and 2 pages of WhatApp messages (no content, just dates and times). So, if you have been together about 2 years, I would provide the following:
- 2 Skype calls per month (date, name and length of call only)
- 2 WhatsApp messages per month (name and date only, no conversation)
Having said that, you only need to provide calls/messages for the times you have been apart, so if you have spent a fair amount of time together, you don't need to cover those periods with calls/messages.