How much RAM? How much SWAP?

This is my third blog post in a row about my new Linux box. See the two previous entries for details.

I asked on the Kubuntu forum:
http://kubuntuforums.net/forums/index.php?topic=3106998.0

Hello,

I am building a new Linux box which will be running Kubuntu 9.10.

I am not playing games. The most memory / cpu intensive things I'll do are: Blender 3D, compiz, file encryption with the archive tool dar, some simple video editing...

I am currently using an old box with a 1.5Ghz sempron and 750Mb RAM only. My new system will be based on AM3 PHENOM II x4 945 and plenty of RAM, so I'll be multiplying my main box computing power by at least 6 to 8!!!

My questions are how much RAM is reasonably enough? No need to waste money by purchasing more RAM for only marginal improvements. I am planning on getting 4Gb DDR3 1600 RAM. Is there any reason for me to get more? Beyond 4Gb, would more make a difference?

Also, it's been a long time I have partitioned a disk. Back in the time when 1GB RAM was considered a lot, it was said that the SWAP had to be twice as big as the amount of RAM. Is it still true today?
How much SWAP is recommended, nowadays?
Note: I'm planning to get a 32GB SSD for the root partition, for the OS. Maybe it's a good idea to put the SWAP on the SSD, too.

In case anybody is interested, are are links to other hardware for Linux posts:

ATI or nVidia graphic card for new Linux box?
http://masquilier.org/node/135
-> plenty of links and relevant quotes.

Graphic card recommendations to use for Blender / compiz:
http://blenderartists.org/forum/showthread.php?t=169177

Thanks.

Blessings,

Augustin.