I would like to hook my satellite box to my oppo udp-205 for two channel audio

An even better idea.
See here for such issues on the usb side: http://archimago.blogspot.nl/2015/05/measurements-corning-usb-3-optical.html

Good idea.

The cable box only has optical out
Using HDMI for the TV
I will get a cheap optical and try that

Thanks

With a long cable I would personally start with the digital coax. More generally, however, inputs are often a scarce resource, so if cable length is not an issue I would use the coax for the source with the highest sound quality (e.g. BD player) and optical for e.g. the television.

pre is c2300 ,,amp is 7b3,,speakers fs-788,,

I will try the optical first

thanks 

no digital out only rca red and white plus optical output

Regarding the possibility of ground loop hum that jea48 pointed out is true. But you (OP) could still go the coax option by inserting a ground loop isolator. Relatively inexpensive ($10?) and they do work. I use one that was provided/installed by my cable company.

What about cable rg59,,,, 2 /30 ft runs and adapters to rca male plugs

I use coax from my UDP-205. This one specifically, but of course there are many coax options. https://www.bluejeanscable.com/pages/technicaldocs/1694tech.htm

My understanding is that digital coax will be cleaner because optical is not really recommended for long runs unless your run is about as straight as a ruler.

Bill