You do get a "free" organ included with Hauptwerk, of course, the St Anne's, Moseley set.
I don't like the strident sounds of many organs, either, so I know what you mean. Before you finally splash out, why not download a few free sets to discover what you really like. Find the "Downloadable (freeware, shareware, trial) Samplesets" section here:
http://www.pcorgan.com/SampleSetsEN.html . Try the Sonus Paradisi 1916, Walcker, Martinikerk, Doesburg, Nederland demo, for instance, or the 1973, Marcussen, Laurenskerk, Rotterdam, Nederland demo.
Salisbury can be recommended but it is quite expensive. Hereford sounds very similar but I have never played it.
I am assuming that you want a church-style organ and will be playing it in a simple stereo or surround set up. Later sets support surround sound. That implies that you will be looking for a "wet" set that has the reverberation of the sounds built-in to the samples. That gobbles computer power but sounds good to me.
The alternative is to pick a "dry" set that has no reverb and does not sound very good until you add some reverb either artificially or by playing it in a large building. Theatre organ sample sets seem to go down this route.