Captden-I would recommend the Victron Phoenix Multi Plus Inverter/Charger with a power factor of 1.0. Here is the datasheet:
http://tinyurl.com/l6d87n
However, you should contact Victron and discuss your genset with them as you have a marginal generator. There is a significant difference in genset frequency control, load management, voltage and frequency stability, and total harmonic distortion. All factors when driving a charger. During the Winter of 2007, Victron did extensive testing of various generators powering their inverter/chargers. A summary report was written by Nigel Calder in Professional Boatbuilder magazine:
Professional BoatBuilder - April/May 2008
Hope this helps and good luck.
Charlie