A few questions, if you don't mind. Are you using sealed lead acid, Lithium-ion polymer, or some other chemistry? Is this designed to be left plugged into the wall at all times? MSRP?
We are using and recommend AGM (activated glass mat) sealed lead acids as they are the only battery that is affordable as well as safe in the house in large AH sizes. The most common size is 26AH. I have a 100AH that I use with my Dodd gear. Chargers that we recommendare the Ctek smart chargers. The bottom line is that you can use any battery combo that you wish. We do not and will not deal in battery sales or chargers. Too many other people sell them at great prices and I have no desire to be lugging around batteries getting them prepared for shipment.
We are dealing in what happens AFTER the battery. I have designed and built the BatteryBUSS and the guys at Mach2 are doing the conversion on the Mac Mini (2010 ONLY). The earlier Macs do not lend themselves to battery conversion because they require 18.5V to make them happy. I will supply the BatteryBUSS and the cable to the battery with options for the outputs with different size DC power plugs for differing applications.
We do not have a firm selling price as of yet as I stated in my earlier post. It is TBD when all of the quotes that we have out get back to us.
Be advised: this is a very serious conversion for brave souls. You ain't lived until you have seen a high capacity battery in a short circuit!

That is also one of the reasons that we are not supplying the batteries. The end user gets to share that potential liability with his dog or spouse.

Dave