It sounds like the plan is for heavily planted and 'heavily' stocked. Even in that configuration, I think one Fluval FX5 would be more than enough and might cost less than 2 Eheim units at the end of the day. Where you looking for weekly water changes? Biweekly?
Weekly water changes. And I agree with you Vader the FX5 may be the best for the money (would actually love to us one); however, I am concerned about the outputs of that monster. I remember the time I had directing the outputs of 2 305's in my 45 corner and I hear the FX5 really blows!!