Honestly. Get the best set up you can buy with the money you have and then see what morph you can afford with what's left. Better to have a normal bp in a great set up rather than an expensive morph is a poor set up.
I'm not sure if you mentioned you have 500 for everything or just the snake ?
You could get something like a phantom and a mojave and aim for a purple passion. Phantom and mojaves are relatively cheap and i think their stunning. And the purple passion is.
Or if you can afford it. My personal favourite is eather a super pastel axanthic or any pied. Or anything with axanthic for that matter