Need a online backup/storage option..two different computers with different needs..

I am looking for a cloud storage option for two different computers with very different needs. I don’t mind using two different companies if need be.

Computer 1 (Grad student work computer) I need at least 500GB of storage to back up 3 years of data. Currently I have two internal drives both 750GB. One is used strictly to back up the main drive. I would like more of an automatic back up set up. Access to individual files from multiple computers is a plus. That way if I forgot a file at work I have access to it from home. I normally keep my most current stuff sync with a 300GB 2.5” portable drive for traveling but you know how that one file gets left behind.

Computer 2 (home laptop and external USB hard drive) I would like a more of an online storage type account with automatic backup. I would want access to my files via the web. The laptop only has a 30GB hard drive and the external drive is 750GB. Currently I have about 200-300GB of data on the USB drive. I don’t always have the USB drive plugged in, it more of a long term storage drive. It is where I keep all my pictures and other files I want but don’t need access to on a daily bases.

I’ve looked at Dropbox, Mozy, Idrive, Backblaze, and Carbonite. It seems the external drive is making it difficult. I’ve also read that if my Laptop drive is only 30GB but I have 200GB of data this might cause issues.

So I know turn to the hivemind experts. Anyone else I should be looking at? Good or bad experience with these companies?

Thanks