Tiller is ok for small plots, but takes a lot longer than discing. They do make a great seedbed.
A seeder of some sort will help you get proper amount of seed on. For grain crops, too much is about as bad as too little. Too much competition and you won't grow grain, only plants.
Cultipacker is awesome for seed that needs to be close to surface, makes for good soil contact.
Sprayer is great for grain crops, weeds also are competition for available nutrients. You can also spray clover if the grass takes over.
So a lot depends on what you plan to plant!! More equipment is good, just sayin...
I'm going to put some cereal rye in the edge of my clover patch for winter browse in a week or so depending on forecast for rain.