Sounds like you are headed in the right direction.
As far as glass vs acrylic there are pros and cons to each. The biggest ones are glass is heavy and acrylic scratches easily.
As far as the bowfront, I like the look but there are some challenges. Gettin lights that will provide adequate coverage over the whole tank is difficult and viewing and pictures will always be a bit distorted by the curve in the glass. It also adds some challenges when trying to clean the inside edges of the tank. I do love the way they look, but I just wanted to point those things out.
I believe (but don't quote me) you can get a pre-drilled bow front.
Regardless of the tank, I would definitely recommend getting a pre-drilled tank. HOB overflows are a royal pain.
As far as the sump, it is quite simple to build your own. Basically the shole purpose of the sump is space. It holds extra water and holds equipment. They are generally made from a smaller tank and some baffles.
Find out what kind of skimmer they are referring to. There are som great skimmers and there are some lousy skimmers. Be sure you are spending your money wisely.
T5 lighting is a good choice depending on what you want to keep in the tank. Depending on the wattage, number of bulbs and wattage you may or may not have enough light to keep Anemones, clams, and hard corals. Good T5 lights will even handle those but softies and lps will be fine under most T5 setups.
Get as much LR in the tank as you can from the beginning. Adding LR after the fact is going to cause another cycle and you don't want that.
Keep in mind that you must be very patient in this hobby. It just plain takes time.
Another thing you may not be thinking about is your water source. You do not want to use tap water. You need to either buy a RO/DI system or be prepared to buy water from your LFS or somewhere else. Reef systems demand high water quality.