All you really need is the meter and (ON)-OFF-(ON) switch in the lower left corner.
I'd opt for a USB charger outlet instead of the old -- antiquated -- cigarette lighter outlet.
Likewise, circuit breakers would be preferable to fuses. Or, at least, ATO fuses instead the (equally antiquated) glass fuses. (Glass fuses are starting to get hard to find while most grocery and department stores have ATO fuses.)
As a suggestion, before you buy, go poke around Blue Sea Systems website. You don't have to buy from them but you might see things you prefer more ... or better ideas.
BTW - there's two types of lead acid batteries, deep cycle and SLI. Both cost about the same. SLI for your engine battery and deep cycle for your coach (house) battery.
Dual purpose (cough, gag) batteries are a compromise that doesn't do either job very well.
With the right type of battery and reasonable care, your $75 batteries should last 5-10 years or more. (The SLI battery in my van lasted eighteen years before needing replacement ... and I didn't take very good care of it.)
The majority of automotive batteries on the market today are all lead acid ... with a lot of 'technical' jargon tossed about by marketing and sales people who don't really know what they're saying.
(I've written on this topic extensively, in this thread ... a hundred or so pages ago.)
