Seeking some ex-pat suggestions on an upcoming trip-

Hi, My fiancee and I are thinking of doing our honeymoon to Nica.  I've spent a few months across the border in Costa Rica and am familiar with CR, but only briefly traveled north.  (I'm also using the trip to scout out potential properties for a relative thinking of moving down there).

The finacee has never seen anywhere in Central America, so I do need to loop in some of the touristy things.  Is there a Nica equivalent of Arenal?  (I'm presuming no, but worth asking).  Otherwise, she will probably want to see some of the tropical rain forest although I'm pushing for the laid back beach variation (not really rforest, but close enough) such as Manuel Antonio's.  Also, we were both hoping to learn to surf.  I don't really want to go to one of the surf schools, but figured there may be some locals that do lessons.  I don't have an itinerary yet, but this would be for early August.  Totally open to suggestions and adventures.  I'm comfortable getting around by any mode of transit (I did boat, good ole autobuso, shared rides, small plane, etc in CR), but I think I should probably try to make it more relaxing on her and either rent a car (I'll drive as I'm familiar with the vast differences in obeying traffic signals...I laugh typing this, but so true) or pay someone to drive us out to destinations.

Anyway, broad advice or very specific would be most appreciated.  Also, thoughts on a late 50s American couple retiring to Nica who I suspect would want to live within walking distance of the beach.  Ie, where to look at properties.

My many thanks in advance.