Looks good.
Are you doing a dual swingout, or 1 long one?
I'd recommend duals, because the shorter the arms, the less stress you are going to be putting on the spindles and bearings and whatnot.
I'd also recommend adding a bit of an incline from the sprindle to the end of the arm.
That way if when fully loaded you get any sag on the arm it would compensate for that.
I took it offroading on a hardcore trail yesterday....it wiggles as expected, but nothing scary and no contact anywhere or clanking or anything to be worried about.