Ubuntu are based on Debian, so it uses Debian packages, so the .DEB package will run better than .RPM.
But if you really want to use the red hat version (RPM), just download the rpm and convert it using alien. I think the worst that can happen to you, is that the program will just not run.
If it is a production server dont install any packages DEB, RPM, tar.gz without testing them first in a identical test computer.