Hey,
Welcome! I hope you enjoy your new reef tank!
First of all, the Sea Clone isn't known as one of the best skimmers. They've made some modifications to it so it's not as bad as it used to be.
For your lr, the ratio is between 1 and 11/2 lbs per gal. so you could double what you've planned. To save $, you could put 50lbs of base rock down, something like tufa or lace rock are good choices since they don't displace a lot of water, and then put 50lbs of good lr on top of that. Eventually your base rock will become lr.
For the ls, if you're going for a dsb you want about 4inches. I don't know the dimensions of your tank but 40lbs may not be enough either. Again, you can put "dead" sand down and then seed it with a bag of ls.
You'll also want a few powerheads and a quality heater. Note, "quality" heater! Many people have fried their tanks when a heater malfunctions and boils everything.
You'll get many differing opinions on this so I've stuck to the basics. Good luck, and stick with the "patients and research" rule and you'll have far less problems!
Take care,
Dan'l