Yep, Bunnings cut to size, apparently they're supposed to charge per cut but every time I've been in its been free so far.
I told them what it was for and they tried to get as straight a cut as possible; I just sanded down the rest and it seems to have come out ok. What wood are you looking at using? I went for h3 treated 3x2 for a 900mm stand, for a 600, you'd get away with 2x2 easy.
Design wise, I actually half copied si sphinx, with a little more bracing between the legs - making sure you spread the weight out over as big an area as possible is key.
And nope, not a builder, just a uni student doing ecology, thanks for the compliment though