I'd keep the length of spooled rope as short as reasonably possible (80-90') so that you maximize the strength of the winch. Then get an extra 50' of rope for long pulls.
I think that's good advise. Also remember if you have 2 straps, which I suspect you do, that's another 60'. Plus whatever everyone else has...
Is this going on the 40 or the 80?

of the rope. I've got a rope extension already (50' or 75', can't remember) so maybe 90' of 7/16" rope will be plenty with straps and extension as needed. Heck, having just 15' would have been plenty on the GTR 