I've come to like anamorphic DVD to XviD encoding without resizing the source. However more often than not you need insane bitrates that clash with my space requirements. So I guess (if I don't want to go for a different matrix, right now I'm using 6of9 hvs) I have to resize. But how?

My source is PAL anamorphic material with an output picture aspect ratio of 2.35.

Should I resize to the correct aspect ratio? I'd have something like 720x304. Or should I resize proportionally without changing the aspect ratio and encode anamorphically from the lower resolution source? In my case 608x368 for example.

I don't change the source aspect ratio in my encodes. I just resize proportionally to a lower resolution after cropping all black borders of course. AFAIK the human eye is more sensitive to lower vertical resolution than horizontal. So playing anamorphically seems like a better idea.

Like you suggested, I went the resized anamorphic route and the result is excellent.