I kind of want to have the top of the line/best performing mod chip since I want this to be a one time job and not upgrade every 6 months or something.
The price of a chip has NOTHING to do with how reliable, or upgradable your mod will be.. If you can solder then go for a duox2.. Beyond that, I'd opt for a softmod since they are just as stable if you read about what you are doing, and you never have to worry about your chip coming loose if you traffic your xbox around..
Basically you can achieve the same end result with $150 for an xbox, and about $100 for the hdd if you hotswap to install a softmod (or if you have free access to items needed to gamesave..
Expensive chips don't actually allow you to do anything special (except possibly lcd screens).. They're more or less designed to perform functions on the chip that could be as easily accomplished with free software or a Cromwell bios.. Furthermore, the functions on some of those chip OS's aren't as safe as the software alternatives.. (On some chips the eeprom backup is easy to accidently overwrite, and the locking function does not set a master password..) This kind of thing can leave a noob who thought his big chip is godly, thinking if he hadn't have blown $80 on his modchip that maybe he'd still be able to unlock his 300GB hdd..