Solar question. Two panels same 24v , Series/parallel math

OK I got the green light from the admiral to get my MPPT..

I have one question...

Should I get the Tracer A series?? 169$ with everything..

http://www.epsolarpv.com/en/index.php/Product/index/id/653/am_id/134

https://www.amazon.com/EPEVER-Controller-Display-Battery-Charging/dp/B077HHYYHT/ref=sr_1_10?ie=UTF8&qid=1514408878&sr=8-10&keywords=EPEVER+40A+MPPT

Or whats the difference in the BN series... I see 219$ for everything?

http://www.epsolarpv.com/en/index.php/Product/index/id/571/am_id/134

https://www.amazon.com/EPEVER-Controller-Regulator-Battery-Charging/dp/B077HQPV1Y/ref=sr_1_10?ie=UTF8&qid=1514421847&sr=8-10&keywords=tracer+4215bn


Im trying to read through the spec but am not sure why they carry two same units that do the same thing... maybe I am missing something IDK...