I want to become a BIOS modder

Manufacturer: Sony
Notebook Model: VAIO VGN-N250E/b
Motherboard Model: MBX-160
BIOS Revision: R0070J4
BIOS Type: Phoenix BIOS
BIOS Download Link:

  PhoenixTechnologiesLTD-R0070J4.rom (Size: 1 MB / Downloads: 0) <- UntouchedBIOS.ROM

  R0070J4-INTELMENU.ROM (Size: 1 MB / Downloads: 0) <- Modded(IntelMenu).ROM

RW Everything Report Download Link:
  AcpiTbls.rw.doc (Size: 237.01 KB / Downloads: 0) <- (I had to put the ".doc" extension on the end of the file name, because the site wouldn't let me upload it, just remove the ".doc".)

I want to modify my own BIOS (to add options/menus) and eventually participate in the BIOS modding community. I have already succeeded in enabling/disabling features (AHCI, VT-x, Service/Repair Mode, Phoenix Info Screen, adding items to boot menu, etc.) using the NVRAM registers. In PBE and HxD (Hex editor), I have succeeded in adding a hidden Intel menu and placing options in menus of my choice (I used PBE as an emulator). I have learned to find token IDs' function(s) by tracing strings to their respective token id's in TEMPLAT0.ROM.

The problems I am having are as follows:
1.) I need a guide on how to create a flashable BIOS dump.
2.) I have read about PBE causing problems when extracting and/or repacking the BIOS. How can I safely (as possible) unpack and repack my BIOS?

For creating a flashable BIOS, I know I need some kind of configuration/platform data from another BIOS update.exe (same series, same chipset). I've already extracted a .wph file (UniExtract) from a R0030J4 BIOS (
  R0030J4.wph.rom (Size: 1 MB / Downloads: 0) (again, I had to add a different file extension for it to upload, just remove the ".rom")), but I don't know what to do with it...

I know that I am asking for a lot, but this will allow me to start modding BIOS's. Any help is highly appreciated. Thank-you.