nguyendot1 - if you live near LA, you can go to one of the LAcomputerfair shows and pick them up for like $1/piece (if you are looking for BNC>RCA adaptor). I used them for my SuperGen SX on my amiga in the 90's... although i got rid of that already - i stopped using Substation Alpha and Jacosub for a while.
Kremerica - for that type of question, i'd post on avsforum. they have many debates on quality issues, but this type of question sounds like it would be easy enough for them to answer without making a 100 page debate.
As for cables, I did a lot of testing with cables and connectors when i had access to expensive equipment at a university (nice ocilloscopes)...
In the end, I found a few results: cables have varying degrees of quality. there are some really crappy cables out there. you don't have to spend a lot of money for decent cables, you have to spend more money for better cables (out of spec use). the logic of "digital is there or not there" may sound correct, but that is not the whole truth.