Getting a tiller is the best thing for tilling compacted soils deeply. A slit-seeder is possibly the best machine for seeding, but seeding by hand and lightly rake in works better.
Aerators will hopefully not be necessary. Starting a lawn from scratch is the perfect opportunity to do it right and eliminate common problems.
What climate zone do you live in and what kind of grass do you hope to grow? :)

How much of a large area are we talking about here? How compacted is the soil? Can you push a large screw driver into the ground easily? What is your goal for the lawn after the grass germinates? I think once we know the answers the better tailored advice we can give.

After reading these forums for 12 years, I don't think any machinery is needed. A slit seeder makes things somewhat easier, but it's not needed.

Tillers are actually counter productive immediately and over the long run. The first thing they do is mix up your soil microbes so those that only live at certain soil strata die off. They'll come back but why go to the bother of killing them? Over the long term tilling causes your soil to become bumpy. Your soil already has developed a structure whereby water is absorbed (perhaps poorly) and air is exchanged. When you rototill that structure has to become reestablished. While that is going on, the soil is settling. The rototiller will have left the underlying soil surface bumpy and when the fluffy soil on top settles, it settles down to the profile of the bumpy subsurface. There's nothing you can do about that except run the rototiller from a tractor.

But still, unless you play football on soggy ground, your soil is not compacted. It is much more likely to be hard from being in poor health. Soil actually can be unhealthy. That results from the loss of "normal" populations of the beneficial microbes that live in the soil. When these guys are unhealthy or dead, then your soil is unhealthy.

By far the fastest and easiest way to get them to recover is to apply shampoo at a rate of 3 ounces (or more) per 1,000 square feet. Then water that in with a full inch of irrigation (or rain if you can arrange that). Give that 2 weeks to work. If you can water and feel the soil being much softer, then it worked. If it doesn't work the first time, try it again. It took my soil two applications to soften up. You can use any shampoo that you can see through. Don't use the shampoos with conditioners, hand sanitizer soaps, or dish washing liquids. I like generic baby shampoo. You can apply any day of the year but preferably when the grass is not covered with snow.

If you are going to answer mightyquinn's questions, then please also tell us where you live. Sometimes that's very important.

A slit seeder can be set so that it just barely scuffs the soil. It drops the seed into the tiny furrows it creates. Then you can come back over the loosened surface and roll it with a water fillable roller. Then start watering and you should have grass in a few weeks.