First forget the rotor till as this will only bring you a bumper crop of weeds and leave you with a very bumpy uneven surface. Hire a contractor with a tractor and box blade. It will take him an hour or two at most. He can bring in the topsoil you desire and when finnished will leave you a perfect, level, and smooth seed bed ready to plant. It can all be done in a single morning, like have the contractor show up at 08:00 and by noon you are watching TV.

I agree w/ TW, just make sure to mark your irrigation heads so the contractor doesn't tear them up. You might have to raise some of your heads as well if you are adding 1" of topsoil. I would wait until fall to do it though...the results will be much better. If you want some coverage before then, aerate and throw down some seed now to get something going for this spring/summer. This is assuming you will be planting cool season grass. If you are planting a warm season grass you should wait until late May or June before planting from seed.

For cool season grasses fall is the best. If you do it in spring you will likely get more weeds and more of it will die in the heat.

But, if you accept that and want to get started to have something until you do another overseed in the fall, you can do OK. In my first house I did a spring seeding of fescue and it turned out great... after wife and I spent hours pulling weeds.

Also, remember the first year you will have to watch it closely and likely water more often. If you don't have a really bad summer and water restrictions don't keep you from giving it enough water, you can really have a nice yard from a spring seeding.

For grass seed, there is a Lesco store in Cary, on James Jackson Ave. I bought a 50# bag on their transition blend that I overseeded with in the fall that I'm happy with. I shopped around, it was the highest rated NTEP varieties I could find locally. With the description of your yard, you could be my neighbor. I don't know about the roto tilling, or box blading. I've always had good luck by heavily core aerating, top dressing, then overseeding heavily ... in the fall though.

Here's some links you might find useful.

Town Of Cary water restrictions FAQ:
http://www.townofcary.org/depts/pwdept/water/waterconservation/waterconsfaq.htm

NC State Turf Files, including guide on Spring Seeding:
http://www.turffiles.ncsu.edu/

NTEP Tall Fescue results for Raleigh, NC:
http://www.ntep.org/states/nc1/nc1_tf.htm

http://www.lesco.com/

I'm in Holly Springs, NC and re-did my lawn last summer. Luckily the lawn was established before the drought was made official and water restrictions were in effect. My bermuda looks great, although it has some weeds--which I'm about to take care of with some RU. If I were you I'd go with bermuda. The NC legislature is trying to pass a bill that will force differenct manicipalities to share water supply systems when necessary. This means that Cary and Apex will share the Jordan Lake resevoir with Raleigh and Durham when their reservoirs are too low. What does all this mean? It means water restrictions could become more of a state mandated thing than a city or county thing. Fescue needs too much water and who knows when you'll be able to water with your sprinklers again. Just my 2 cents.

mmqb, I have enough shade from tree throughout the day that my lawn will not need a ton of water. Only one spotot in my lawn will get sun all day. I though about a warm season grass but I don't care for the lon brown periods. Cary has always been forward thinking and even when water was/is plentiful, they only allowed watering 3 days per week.

I would hate to see Cary get sucked into the abyss of mis-management of other municipalites such as Durham (*SHUDDER*)

Geez, I need to use the spell checker when I post . . . It looks like this bill is going to pass. When it does, all mandates will apply for each town that uses a specific reservoir. Cary was the last town in the triangle to move to the last stage of water restrictions. This will not happen when Durham and/or Raleigh ties into Lake Jordan. When one town needs to go on restrictions, everyone will. I would hate for you to spend all that money on your lawn and not be able to water your grass. You can have a green lawn year round by overseeding the bermuda with winter rye in the Fall. The rye will die off in the spring when the bermuda leaves dormantcy. Any way, good luck to you with whatever you decide to go with.

With as much shade as you have, Bermuda will not survive.