upgrade's on boat

[adamsfence]

ok guys i'm going to put some upgrade's on my boat was going to put trim tabs and jackplate but i think i am just going to go with the jackplate and put the trim tabs on later......i also am going to get a chartplotter i know everyone is sold on garmin (including me from the handhelds) My question is what series is the best for the money. I have been looking at the 420s how much better are the upper series and is it worth the extra money. I mainly fish big lake but i do fish alot at toledo so would won't something that is good on both

thanks
adam