An unofficial 64bit port of Slackware recently apeared.
You can check http://www.bluewhite64.com/news.php for more info.

As for Debian, you can check http://www.us.debian.org/ports/amd64/

Slamd64 has been out for over a year. Did you know about it?

I think Slackware and Debian are about the same in day to day use. I've installed Slackware twice and found it easier to install than Debian. Every time I installed Debian, I had to do some extra work to support at least one or two pieces of hardware.

Slackware is simpler. Plus, learning Slackware teaches you things about Linux and Unix, period. It makes your knowledge more widely applicable. Because Debian does some things its own way, not all of your Debian knowledge transfers to other distros.

On the other hand, new package installation and upgrading existing packages are much easier in Debian thanks to "apt". The automatic dependency resolving, in my experience, is much more convenient than Slackware's pkgtool or the different RPM tools.

In the end, I think it boils down to how often you're going to add new programs after your initial setup is complete. If your box is going to remain relatively unchanged, Slackware is a spectacular choice and there's no real reason to change. Otherwise, I would go with Debian.

another thought is zenwalk, the very fast slackware based, small distro that uses slack packages and it's own, and has up to date packages for most apps. It has a system called netpkg that is similar to apt-get.

I wouldn't dream of having even a single box without the option between slack and debian. In many ways they are examples of excellence from different points of view. When I want fast, simple configuration, without loading thousands of apps and app makers, and guis and gui makers and configuration options and ways to handle pkgs? i boot slack....when i want the complexity and choice of applications that debian offers, i boot debian. I like the debian option of over 17000 pkgs and the depth of the system and its maintainace, as in the development model, the commitment to free software and the ability to choose stable , testing or sid.....it is a helluva lot more complex in size and scope than slack.

When i want the simplicity of some basic packages to do my work, a system that runs fast and when something goes wrong its easy to find, i look to slack. They are both free of obnoxious config tools thtat get in the way but one is smaller and simpler and one is sprawling and universal and extremely morphable. Why choose only one distro for everything?

Besides with VMs all the rage these days you dont have to wipe one system to try another....although i sometimes get confused as to whether im running the slack hacking box virtually in debian, or the debian sid box in slackware.....

To sum up? My answer is running Debian and Slack.

What `gui/gui makers` are you talking about ?
Debian is more of `roll your own` distro. It doesn't stay in your way. To be more
concise, Debian is how you make it. You can have it simple and easy to maintain,
or go for the `gui/gui maker`.

I was thinking of most other distros rather than debian....i think both slack and debian are roll your owns at their finest, heh...

There are however alot more debian tools available (not necessarily gui tho) if someone wants to hack their system every which way but loose.....compared to a certain streamlined simplicity with Slack. As i said earlier both have their place and i wouldnt dream of having to choose one exclusively :-)

Cheers