Hopefully you will have more responses now that your goals are clear.
Do you want both a Howard Rotovator AND a Disc Harrow? Both these implements are soil mixing TILLERS, in different forms. Usually it is either/or, not both.
As you have sand, perhaps the Rotovator, then a heavy Landscape Rake with gauge wheels or the Rotovator, then a heavy Land Plane/Grading scraper in lieu of the Disc would give a faster, better result. In sand, a Landscape Rake can accomplish everything a Chain Harrow will do. (Everything Attachments produces excellent Landscape Rakes.)
For sand based soil I think a broadcast spreader would be as good as a seed drill. For 80 acres I would consider a Cultipacker to roll in the seeds. A Cultipacker leaves 2" ridges pressed into the soil, which do final flattening of clods, prevent soil erosion until seeds germinate and improve seed germination through solid soil contact.
I use Buckwheat around organically grown Blueberry bushes to reduce hand weeding with a Korean Hoe. Every Buckwheat seed germinates. The Buckwheat dies about now, just before Blueberry harvest in Florida, which is convenient. This Fall I plan to experiment with Annual Rye as a cover crop in one or two Blueberry rows to see if I can reduce weed cultivation with the Kubota BX tractor and increase organic matter. Our Rabbiteye BB bushes are planted on 8'-6" centers.
On land that I have cleared from jungle, I have been planting deer food plots, once in late March, a second in September. Food plot seed is cheap and the mix contains strong germinators. When the crop matures I give the deer three weeks to feed, then mow with a Rotary Cutter and disc in the residue as green manure. My Disc Harrow has 20" diameter pans, notched front and rear. It chops the cut residue fine. So would your (excellent) Howard. Some type of food plot seed mix MAY be your cheapest cover crop seed. Commonly $22/50 pounds at Walmart.
A Korean Hoe is BY FAR the best hand tool I have discovered for close Blueberry cultivation:
Amazon.com : Long Handle EZ-Digger : Garden Hoes : Patio, Lawn & Garden
Broadcast Spreaders: PTO Fertilizer Spreaders by Agrex
Cultipackers: Cultipackers For Sale by Everything Attachments
LANDSCAPE RAKE:
tractor Landscape Rake - YouTube
LPGS:
land plane grading scraper - YouTube
Photos #1 - #4 ETA Cultipacker
Photos #5 - #7 'Wunderbar' Modular Tool Bar Cultivator from Woodward Crossings, PA. (I have two.)