Which Sonnenschein for Early 911?

[peecarfan]

I'm looking for a pair of replacement batteries for my 73 911 and I'm interested in Sonnenschein for the size (supposedly perfect fit) and sealed design.

However, there seem to be some confusion as to which models are sealed gel-type vs lead-acid models:

A-500 Series
A512/40.0A
http://www.batterysales.com/sonnenschein_a500.cfm

or

DF Series
DF75
http://www.batterysales.com/sonnenschein_prevailerusa.cfm

Anybody have experience with either? Are these the right models for the job?!