Rikki - I long ago stop reading the crap people are flinging on here... If these people can't say anything constructive they shouldn't be posting at all (not that constructive points haven't been brought up).
I know that you are not the most experienced keeper... Personally I know that even people who have worked with reptiles small and large for years and years and years still make mistakes. If you want to give a special needs animal a home, try volunteering at a vet clinic to get more experience on the medical and rehabilitative side. It's exausting to care for an animal, and if you get one, you may not have much of a life leftover!
It's true, many rescued reptiles are not going to be friendly when they are rescued and handled. Trust me, I know!
It's good that you have the experience you do have... although, I must say I'm not sure why a petstore is letting you run around with an 11' burm. You are still quite young, and that snake has the potential to overpower and kill you if it so wished... and there is little chance that you could be rescued before permenant damage has been caused. This is an extreme risk the petstore is taking with you... (what if the snake overpowers and hurts you? Or, what if it lashed out a customer? I hope you'll never know those reprecussions). Snakes are well known to been unpredictable with persons who have kept them for years without incident!!! Just something to chew on...
Also, I think many people would be concerned with the fact that you 'gave' your iguana away because you moved. (Did you give it away or sell it?) Reptiles, like any other pet should be a lifelong commitment. Like any other member of a family, they go with you when you move. I know it's hard... I have a 14 foot long burm and I've moved with him four times!!!! Some may think that you weren't commited to the iguana... Some might say you gave him away because it was easier than taking him with you... I don't know all the facts, though, but I know this is in the minds of people following this post. They might also be thinking that if you get another iguana, then move, that you'll give this one away too!
I wish you luck, and just as a side note, just because an animal is a rescue will not mean it's free. (Now I know that someone else brought this up, not you); any decent rescue organization will charge you a nominal fee based on 1.) How much the animal is generally worth, 2.) To recover costs such as feeding, vet care, medications, lighting and rooming expenses. AND 3.) Paying a fee demonstrates that the purchaser is not just getting the animal on a whim... Paying money for the animal in itself is sort of making a commitment; like an investiment.
I have so much more advice to give you but I can't right now (I'm at work). Keep learning about your reptiles, and I wish you the best of luck!
P.S. Julie, I just read your post, and whoheartedly agree with you... You summarized it better than I ever could!!! =)