I'm not sure where the crack you're talking about is located, because the "flange" is the thing on the floor to which you attach the bowl. Regardless, what you are planning to do makes sense.
If it were I, I would first read the sticky at the top of the toilet forum for tips on how to install a Drake. I would also read toto's instructions for installing a Drake. That should all you need instruction-wise.
Assuming that you have the ability to lift the bowl and tank when empty, it's certainly a do-able DIY job.
Here is what I would replace:
(1) The braided hose betweent the water supply and the tank. It's typical to replace this when replacing the toilet. Is it critical? No. Is it a good idea? Yes.
(2) Wax ring or equivalent. This new product from Korky seems to be a good alternative to a wax ring.
http://www.lowes.com/pd_586597-868-6000PK_0__?productId=50150240&Ntt=korky&pl=1¤tURL=?Ntt=korky&facetInfo= One advantage: you can wiggle the bowl a little while installing it without worrying about breaking the wax seal; you can even take it up and put it back down. With a wax ring, you absolutely cannot move the thing after smushing it into place. For a newbie at doing this, it may be helpful. I have done fine with wax for years now, but if I were doing it for the first time, I would use the Korky.
(3) New Tank To Bowl Set. You should get a good one, with two rubber washers, two metal washers, and two nuts for each bolt. You install them as follows: Bolt head and rubber washers inside tank; first metal washer and nut outside tank; 2nd rubber washer, metal washer and nut in that order under the bowl to secure the tank to the bowl. Here's a good one, although you don't need this quality, a good brass one will keep you happy for a long time.
http://kscdirect.com/item/SIO+490-10500/SIOUX+CHIEF+MANUFACTURING_BOLT+DELUXE+TANK+BOLT+SET%0A Also, the official Toto one, TSU01D, is pretty good and is available online from many suppliers.
(4) New Tank to Bowl Gasket. Again, not totally essential, but useful. The official Toto one is THU131. That's a set of ten, which you don't need, but some online suppliers will sell you a single one. EDIT: They used to sell a single one, which is model 9BU024E. Google that. It's inexpensive and if you can find that, great. Otherwise, see if someone will sell you a single gasket from the THU131 set.
When you attach the tank, your goal is to watch all three points of contact (see the directions) and tighten the thing side-to-side, little by little, slowly, holding it vertical while doing it, until you are a business-card's thickness distance between the china on the tank and the china on the contact points on the bowl. You may have to release it and start again a few times before you get it level and tight; it took me 3 or 4 tries the first time I ever did it; now it's easy. The donut gasket will resist, and that's what the tank stands on. When you have no point of contact touching but all 3 almost touching, then the tank will be wobble-free and properly-positioned.
You can also get these Toto parts at a local plumbing supply store.