as someone who just recently completed a coupe project similar to yours here's a few things I recommend:
1. before cutting or taking anything structural off the car, jack it up on jackstands as high as you can in a place you can leave it AND work on it, then mark the floor where the stands are sitting. using some type of shims (paint stir sticks work well) get the stands to where the car is putting an equal load on them. this is going to be your reference for a straight car while your working. most of the metal you'll be cutting off is structural and the frame/body will shift out of place when it's cut out. this way you'll always know when the car is "straight" by how it's sitting on the stands.
2. get some good spray can weld through primer. you'll need it when you start putting things back together, the new metal will have some coating on it but it's not all the same, before welding, prime both the new and the old metal with the primer, it will help keep things from rusting in the seams.
3. I bought all my metal from NPD, they are pretty close to me and I had good luck with panel fitment, still took a bunch of work to make them right but they are close. try to buy all the metal at one time if you can, it will save shipping costs. if you're going to be buying a lot of stuff in short time frames, you could go through CJPony parts, they have a buyers club and you earn points on purchases you can use against other stuff, it saved me a fair amount of money during my project, but be warned, the points do expire after a while so you'll need to figure that part out.
4. I should have listed this first but ----DON'T THROW ANYTHING AWAY TILL THE CAR IS DONE
I can't stress this enough, you will need to reference the old parts for things like measurements, hole placement ( for emblems), and God knows what else. this applies to interior parts as well, there will always be that one little part that you can't find anywhere that will hold you up, even if you know you're going to be replacing it, keep the old stuff till you're COMPLETELY done with the car.
5. add this site to your favorites and refer to it often, there is a TON of good information from people who have gone before you, don't be embarrassed to ask a question, if you have any doubt at all, ask first, it will save you a ton of work later on.
6. take lots of good quality pictures every step of the way, they will be good references when you can't remember how things were positioned before you started, they are also nice to look at when done.
7. GOOD LUCK
!! and try to have some fun while working on it, if you get frustrated, STOP, and take a breath, maybe even a day or two off to clear you mind and attitude.