Beachcomber "Copper Cove" wiring

[nehpd]

I am expecting delivery of Beachcomber "Copper Cove" soon. It is rated at 55 amps and calls for #6/3 and no longer a length of wire than 70'. Well, That aint happening because the shortest distance that I can possibly run service from the main breaker box to a cut-off to the tub is about 140'. So, my plan (indeed I have implemented most already...I guess I'm just looking for reassurance or a wave-off if I am asking for trouble) is to run #6 wire (red, white, black, and green) all in individual insulation within a 1" PVC conduit from the GFCI breaker cut-off to the tub itself. That distance is 50'. This part is done. So, now I am trying to decide between using more 6/3 as above for the 75' run from the main breaker (240v/2 pole) to the GFCI cut-off, or if I should use 4/3 for that run. My hot tub shut-off has room for not only the 60-amp hot tub breaker but also 2 additional 20 amp GFCI breakers, both of which I intend to run a couple ceiling fans, a few LED light fixtures, and a couple of wall outlets from one day in the future when I get my patio built. If it was not for this intention, I think 6/3 the entire length may just make it...but that isn't going to be the case.

Also, I am pouring my pad this week and I have heard I should ground the re-bar in the pad with a grounding rod and also ground the tub itself to that same bar. I have heard to also ground the Cut-Off panel with a copper rod, and of course make sure a ground wire goes from the hot tub to the cut-off panel to the main breaker.

How does this sound and does anybody see a better way of doing things?