Can someone help me out with some noob power supply questions?

I'm building either a portable Dreamcast or a portable Gamecube, and I'm buying up the parts right now. I'm looking to power it with two camcorder batteries either in series or parallel. I'm aiming at getting the following batteries from eBay:

http://www.ebay.com/itm/2x-Battery-...291545?hash=item3a9116c459:g:mhUAAOxyx0JThaDO

I was going to have them connect to a PSOne screen as well. I feel I should also note that my Dreamcast has a GDEMU, and my Gamecube will have a Wasp and MEGAdrive v3 installed. SO, here are my questions:

1. How would I go about having the ability to charge while the batteries are in the system?
2. Is putting those batteries in series and/or parallel feasible?
3. Without a disc drive installed, will that lower the power requirements for the portable?
4. Would a PicoPSU provide any benefit? Perhaps to take the power from the wall into the system and then somehow taking those power lines into the batteries?

I apologize if these are stupid questions, I just know this forum is filled with fucking geniuses and I don't know where else to ask!

 

One of our forum members - bacteria; built a portable Dreamcast. Here's his post from a few years back.

Step-by-step guide to making a portable Dreamcast console

The guide is on the Instructables website.

As an additional reference; also on Instrucables, you should probably read through this guide first: How to make a portable game system