Skype is a 32bit binary. You can't run it in any 64bit distribution. Unless of course you also have 32bit libraries installed in your system. Google for "multilib slackware" if you really want to do that.
To make e.g. skype work, would it be advisable to try the multilib? Of would install salix 32bit be a good idea. I also want to install skype, but also want to try the citrix software to log in at my work.
If you don't have more than 4G of RAM there is no compelling reason to go 64bit. Even more when you need strictly 32bit apps like skype or wine. Multilib is something that is needed for people that need 64bit, but also have to use some 32bit apps.