+ Devon, who might know if we can download a separate 64 bit Dart SDK for Linux. (we have a dart-linux.zip now, not sure if that's 32 or 64?)
I'd vote for Dart on Heroku:
https://github.com/igrigorik/heroku-buildpack-dart
I think we're bundling the 64 bit Linux SDK into the 64 bit Linux Editor download, so Dart on heroku might be a slight bit easier.