Here are the options that i can think of so far:
1)Is it acceptable to have a vent pipe that extends upward @6" from the
trap, then back down into the basement to connect to the vent pipe
there? Or do i have to have the vent pipe travel upwards and over to
connect to the vent pipe above the highest trap in the house?

Vents go up, not down. Your description makes an inverted "P" trap. ( at
least in my mind )


Well, mostly, but they do do that sort of thing for island sinks.
I do not know for sure, but I suspect that the upward loop of the
vent pipe has to go higher than the flood levels of all of the
fixtures is serves.