everyone has their own limits, budgets, etc, etc.
i general, i always suggest getting the largest screen unit you can physically install and able to afford.
a couple years ago i upgraded my electronics on the 282 and it has been a tremendous improvement.
I'm not overly particular on brands as i've had Raymarine, Lowrance, Humminbird and Furuno and been happy with the application for each.
IMHO, for the 208, i'd highly suggest the Lowrance Elite 7 HDI. No direct personal experience with that unit, although have had some LCX series unit and at $699.00 full MSRP, it's a tremendous value. Easy and clean install due to internal GPS sensor, integrated sounder (lowrance sounders generally very good given their price), wide full 7 inch screen allows for very respectable split screen duties, and Lowrance quality is generally good. Unsure of their service but have heard it has been vastly improved. I also have a preference for Navionics maps, so Lowrance fits that bill too.
you may consider standard horizon combo units. generally their hardware performs well and their service should you ever need it is very good. for smaller boats, i really like combo units and SH makes ones with plotter, sounder and VHF. definitely unique to SH. the combo units use C-MAP charts (OK, but again for my area i prefer Navionics). Having redundant systems is great, but on a 20`boat you`re limited to space and i`d image not terribly interested in spending 1000`s of $$$. BRING on the COMBO UNITS with integrated components!