Garmin lake maps question

I have had a lowrance h20 ifinder for a few years and have not been very impressed with the accuracy of it.  I recently found a garmen oregon 450t for a steal of a price and am now in pursuit of buying lake maps for it.  My question is that there is lake master dakotas, but there is also the inland lake vision for the north certral region.  This inland lake vision covers MN, Dakotas, Iowa, MO, IL, IN, OH, MI, and WI.  So it seem lik a much better deal than the lake master that covers just the dakotas.  I want the maps with the most info on them contour, accurate, depth readings (change by 1 foot incruments) ect.  Does anyone own, or know anything about the differences between them.  I am comfortable with buying maps for each indivual state as I need them if they are more accurate that way.