Jochen,
> Are there some rpms for SuSE7.3 available?
No. In fact, I would not expect them until the release of SuSE 8.0.
For quality-control reasons and for YAST-compatibility, SuSE Inc.
builds their own distribution RPMs (as opposed to accepting RPMs built
by the online community). As a result, you can expect some waiting.
In the meantime ... PostgreSQL is really one of the easier applications
to compile. Go on, give it a try. You know you want to.
-Josh