Ross and Tom talked about it some in Episode 115:
http://slangdesign.com/rppr/2015/06/podcast-episode/rppr-episode-115-the-agony-of-choice/.
But it hasn't been a big topic, since RPPR is mostly about in-person gaming.
Our podcast, Technical Difficulties, is all online. We've had good luck simply playing over Google Hangouts, and sharing any files/character sheets/handouts through Dropbox or Google Drive. We try to keep our tech setup as simple as possible, since (as our name implies) we don't always have the most reliable equipment.
Personally, I've also had a little bit of experience playing on Roll20. I didn't much like it. The interface was too clunky and hard to manage for my tastes. I didn't feel that it added sufficient value to make up for the hassle of wrangling with it.
As for your specific issues, maintaining tone and finding players:
Tone is very hard to maintain online, since you can't control anyone's sources of distraction (and I personally admit that I get easily distracted when I'm playing instead of running an online game). My biggest piece of advice is to keep your group VERY small - like 3 players maximum, and make sure that no one ever has a long stretch with no actions or decisions to make. Keep the game constantly moving forward, and make sure to specifically call on each player when you want them to do something.
For finding players: my only suggestion is to stop trying to find randos through Roll20 or whatever, and look for people in places where you can share interests a little bit and get a read on personalities first. Like in this forum! The whole Tech Diff crew met here on the RPPR forums. Give yourself some time, and be patient.
You might also find some better advice over on the
Drunk and Ugly podcast's forums, since they're an online gaming podcast.
