You rock! Thank you, it's definitely appreciated, especially when we realize that our users have already shelled out some cash to subscribe.
We do normally charge hourly, but right now, we're not taking on any new clients for the foreseeable future. We're mainly trying to focus on our extensions a bit as Facebook is becoming even more desired for Joomla (it seems) and Facebook is on a kick to keep adding (and changing existing) features. It's a race to stay on track with them, which is both fun, but a bit stressful when they launch stuff without warning (especially when it breaks what they 'launched' last month..)
If you want recommendations for great developers, we recommend:
edgewebworks.com
corywebbmedia.com
Hope that helps, and good luck!