Are there any commercial nodes available so my transactions won't show my IP address? Oftentimes my own IP address shows up as the "Relayed by ip" piece of data reported by Blockchain.info.

Is there a commercial node available that I can conract with to act as relay so that my IP won't be known?  (and has as part of the agreement their assurance to not log IPs for transactions)?

I know there are certain well connected nodes that I can connect to, but I don't have the guarantee from them that they aren't collecting and sharing my IP info.
Bitcoin will run over Tor. There an article on the Bitcoin wiki that explains the process.

Just install Tor and let it set up a proxy on its default IP (127.0.0.1) and port (9050). 

For bitcoind, use the flag --proxy=127.0.0.1:9050.

For the GUI client, under Options, check Connect through socks4 proxy. Set the proxy IP to 127.0.0.1 and the port to 9050.