CDN recommendations?

Hi, everyone!

I’m currently using Mutli-DB with 4096 databases and am looking at better optimizations (and hey, SoftLayer has a nifty deal on new dual-quad servers right now)…and CDN is really ideal. I’ve got over 90gb of uploads I’d like to push into the cloud. At SoftLayer this would cost me only $38/mo.

1) Has anyone used any CDN plugins with SoftLayer’s “CloudLayer” service…and how did it work out? The same space and bandwidth on other CDN services will cost me at least 3x as much. I contacted their sales dept, and the person I talked to said it wasn’t even possible to use WP with their CDN. But he was clearly just an idiot.

2) Can anyone advise on how to integrate a CDN plugin (like W3 Total Cache) into a Mutli-DB setup? My last attempt (with WP Super Cache) hosed the Multi-DB configuration, and I’d like to avoid that if possible.

At this point, I’m pretty sure I can get W3TC to work with SoftLayer for the CDN (at the very least, thru FTP)…but I’m afraid I’ll have issues related to Multi-DB. I’d love to hear about experiences and recommendations from anyone who has tried this already.