right well a rgh is a the same as a jtag except that a rgh can be done on more of the recent dashboards so they are newer consoles less prone to rrod falcopns arent as good as jaspers as they still rrod not as often as xenons and zephyrs tho the flacon v2 motherboard is just as good as a jasper tho a dual nand slim is basically a rghed slim with a toggle swith were if it is flicked one way you have a retail nand so you can go on xbox live then if you sawitch it the other way it is a jtagged/rghed nand so esetially you have two consoles in one you can use your regular cables for it however if you are planning on doing systm link mods so yolu can mod onlinethen i would get new cables so you can have both consoles running at the same time the best hard drive is a size that is suitable for you and the amount of games yopu want to install to it but idealy 120gb up on a jtag/rgh yes you can preload the hdd and still have xexmenu (xexmenu is a game demo wich alowws you to change files in your games and load the custom xex this is how lots of people preload there hard drives and the best rghed console out of the lot would be a tie between a rghed slim and a rghed jasper slims are good but if it breks it will be realy pricy but if the jasper breakjs not as pricy

My opinion I dont think there is really any diffrence except the falcon might heat up a little faster. you can use same cables but if youd like to do system link lobbies your guna need to xbox's so you will need another set of cables and power supply. HDD all the same i usually just use 120GBB you can put a lot of games and aything you want on there. if you buy a preloaded hdd it will hav xex menu on it with alot other stuff! Id say go with jasper or falcon! that is my opinion.