I'm looking for online retailers that sell vinyl records put out by the record 
labels Perlon (Germany), Soundslike (UK?), and Force Tracks (Germany.) I would 
like to be able to listen to audio previews of the tracks before purchasing.

Here's a list of web pages which sell records from those labels:

Perlon 
======
1. Homebass Interactive. 
http://www.homebass.ca/label/l1916.cfm 

2. Paper-doll .com (no audio previews available)
http://www.paper-doll.com/site/records/disp_label.cfm?Label_ID=12 

3. Forcedexposure.com http://www.forcedexposure.com/labels/perlon.germany.html 

Soundslike 
==========
1. Nu Loop Online Record Shop ? (preview audio tracks and buy)
http://www.nuloop.com/SearchE.asp?affiche=LabSearchE.asp?label=SOUNDSLIKE 

2. Basement-trax (France)- (no audio previews available)
http://www.basement-trax.fr/catuktechno.htm 
To order, send email to basement-trax@libertysurf.fr 

3. Hedonizm Records (UK) ? (no audio previews available)
http://www.hedonizm.demon.co.uk/nr020701.htm 
To order, send email to mark@hedonizm.demon.co.uk. 

4. Hardwax.com 
http://www.hardwax.com/mailorder/d_labels_1.html 
Herbert Bodily Functions K7 097 / Soundslike an appealing mix of high class
house, jazz & modern production skills Mail order - no audio previews available 

5. Epitonic.com ? preview and download music only.
http://www.epitonic.com/artists/herbert.html#tracks 

6. Methew Herbert home page
http://www.matthewherbert.com/Herbert/Soundslikeindex.html 

Force Tracks 
============
1. ForcedExposure.com ? (no audio previews available)
http://www.forcedexposure.com/labels/force.tracks.germany.html 

2. Homebass (audio previews available) 
http://www.homebass.ca/label/l1470.cfm 

3. Force Tracks main website http://www.force-inc.com/ft/ 
http://shop.force-inc.com/jump.php4?entry=ft

Great answer!