When it comes to capturing memories...why risk it?
With older digital cameras, it is first and foremost a good thing to make sure you're on the most up to date firmware. Firmware updates usually involve updates to the communications with CF cards.
Secondly, you have to remember that the camera tech was built around the storage units of the era. For example, I still have a 20D - and I also still have a ton of 1gb, 2gb, and 4gb cards for it. It's almost like shooting film when I load up the 1gb card on my 5Dmk2 - but for the 20D, it's decent enough space.
If 8gb is the most that the 350D will recognize - then I would say your safest bet is to find an 8gb card and have the camera format it. Get 2 cards and use them instead of 1, 16gb card.
Note: My perspective is coming from working in a photo studio where the heavy use of our cards absolutely led to cards "going bad" and spitting out corrupted images. It is far better to shoot with a few, smaller cards and to have one go bad on you than it is to use a single card that flops.