DIY Audioadaptor

[Fabian Henze]

Hi,
I was about to solder myself an adaptor to use my headphones with the 
FreeRunner as an ogg/flac player. I have found some jacks, which seem to good 
for this task (german website):
http://www.reichelt.de/?;ACTION=3;LA=2;GROUP=C161;GROUPID=3237;ARTICLE=47784
http://www.reichelt.de/?;ACTION=3;LA=2;GROUP=C161;GROUPID=3237;ARTICLE=47785
http://www.reichelt.de/?;ACTION=3;LA=2;GROUP=C161;GROUPID=3237;ARTICLE=9410

Now I wonder, whether
a) the jack inside the fr is compatible to the ones of reichelt?
b) I just need to connect the jacks with a proper cable or do I have to solder 
some resistor, capacitor or sth, different in between to work around the bad 
sound quality some people have noticed?

-- Fabian