I haven't tried the Thinware product yet, or played around with trying to schedule VMWare Converter.
The Veam FastSCP product was what I really wanted to use, but the latest version (that works with VSphere 5) is wrapped into their backup product that can't be scheduled unless you pay for a license. While reasearching the older version's vSphere 5 compatability (some said it works with 5, some say it doesn't) I saw several people talking about using WinSCP and SFTP tools to do what I was looking for. However, WinSCP seemed to to work for some and not for others with the large vmdk files - which is why many posts said Veam FastSCP was created. Too bad it's no longer available 
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However, while reading through all the SCP and FTP threads I remembered that GoodSync (a Windows/Mac Tool) can connect to all kinds of networking sources for it's scheduled jobs, including SFTP sites, so I gave it a try and it worked for a small 5GB VM. I'm reinstalling the environment now and I plan to do more testing on larger VM's (up to 40GB) over the next few days. If not i'll try converting the VMDKs to multiple 2GB files instead - I was going to try this anyway to see if it would cut down the nightly backup traffic - I was hoping that if I defrag the drive that not all of the 2GB files would change every day.
I'll report back in a few days to confirm if the tool works or not, but I'm guessing this is probably more of a 'hack' solution than you are looking for though 
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