Hi! 

What did you use in past? Check what we have in GeoPard Ag. 

You receive not only ndvi and other indices mapping, but also the whole stack of precisionAg data analytics. If you use JD Ops center - you can sync any map layer in both directions (have imagery and soil, topography, rx data in the ops center).

Several helpful links: 
GeoPard docs portal
Satellite imagery modules (per field or regional)
Advanced vegetation & Moisture indices . As you probably know ndvi saturates when ndvi > ±0.7, there are some other indices that better reflect vegetation
Accurate clouds and shadow detection - check this carefully, some of ndvi pictures you receive from other providers have clouds and shadows, because they don't run field level detection of these artifacts.


Hope it was helpful, we can set a free trial account for you (drop me an email or send message here). If you have MyJohnDeere Ops Center account - just login with JohnDeere here  & start using it for free on up to 250 acres. 

P.S.: working in precisionAg for > 10 years, built software for major ag input companies in past.

Cheers!