O.K: so I am thinking about buying a Nintendo DS Lite, either new or used at Gamestop. I am also interested in hacking the DS Lite for homebrew and other hacks, but I dont wanna screw myself over and I decided it smart to ask these questions on a forum

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1) I have researched and discovered the DS Custom Firmware allowing you to use emulators on DS...what is required to have this done, and is the process easy or the same difficulty as installing PSP Dark Alex CFW?
2) What will this DS Custom Firmware allow me to do...ex) ISOs?
3) Will all of this hacking work on any Nintendo DS Lite?
4) If no to question 3, what should i look for when purchasing my DS Lite?
5) I am aware that installing DS Custom Firmwmare requires some sort of GBA Cartridge or DS Cartridge allowing me to place the Custom Firmware instillation files on it. I have watched multiple youtube videos of people installing CFW on their DS, but they were using a GBA cartridge, and when they were using this cartridge, they had to knife out a part of their ds...will the DS cartridge work also?
Well thats about it...sorry for the super long post and super long questions...but i want to be sure I know what I am buying.
I am planning on buying the DS by the end of the week so quick reply would be apprciated
THANKS!!