Re the S-Video connection:
As TerryB points out there are VCRs out there (S-VHS) that have S-Video connections (both in and out). Also most DVD recorders that I know of have S-Video inputs (and outputs).
S-Video connections came about when the technology was developed in VCRs (S-Video & ED Beta) to record a higher resolution picture (took horizontal resolution from around 240 lines to 400 lines). This resulted in a problem with interference between the luminance (Y - black & white) and chrominance (C - color) information. By putting these two signals on separate lines this interference could be avoided.
Here is a 50ft S-Video A/V cable for $20http://mcm.newark.com/NewarkWebComme...U=24-6360&N=4.
They also have a straight S-Video cable for $15http://mcm.newark.com/NewarkWebComme...KU=24-7335&N=4
I can't vouch for either of these but am suspicious that the capacitance in the typical S-Video cable may well cause problems in a 50 foot cable. The approach that professional installers use is to split the Y & C signals using an adapter like this on each end of the run:http://mcm.newark.com/NewarkWebComme...KU=24-9000&N=4
They run low capacity coax (with BNC connectors in this case) between each end. It is important to use the same type and length of coax for the Y and C.