you think long and hard about just why you want a rattlesnake...no offense, but frankly, and I'm sure others share the sentiment, your post really scared me. It appears that you simply want a rattlesnake because it is a rattlesnake, with no forethought to the immense responsibility on the part of the keeper when keeping such animals. Small or large, rattlesnakes are VENOMOUS animals and can and will hurt you (or worse) if you do not know what you are doing.
Are you prepared to put your safety as well as your FAMILY's in possible danger?
Do you have health insurance? Will your insurance company cover a bite from a CAPTIVE venomous reptile? If not, do you have the $30,000 in your bank account to cover a bite if it happens?
Do you know a doctor who has experience treating snakebite? Most doctors in the U.S. have ZERO experience with any venomous snakebite, and often times perform procedures when they are not warranted (i.e. fasciotomies), or otherwise incorrectly treat bites. This can lead to disfiguring scarring as well as other nasty side effects.
And most importantly...
Do you have any prior knowledge and experience with venomous reptiles? You post leads me to believe no, you don't.
And lastly...
Are you prepared to risk serious injury/death just to keep a snake?
Ask yourself these questions...and think long and hard about the consequences of getting a venomous reptile on impulse. These animals are NOT tame by any stretch of the word, and if you give them a chance, they WILL nail you. A bite from some species is not too severe, but others can kill you rather easily. Take the advice you've been given from the other posters and myself and take baby steps in this hobby, you will be happy you did.