What should I get and what would I need

I am about ready for me second snake. Should I get a red tail or a tree boa of some kind and what kind of supplies should I need for both within the first year? I am itching for another baby, but I don't know what to get. Suggestions and experiences are also welcome.

how big of a snake would you want?

oh, not much bigger than 10 feet. A male of the larger specie would stay smaller than the females, so I will probably go with a male. But I do want a large one

bci's are great, and the price is right. Their care is simular to bp's, they just need alot more space.

Argentine boas are niiicee. They are a bit more expensive. They are pretty active as far as boas get.

If you decide you want to look into aboreals, study lots. Their husbandry is a bit more difficult then most. I would suggest an Amazon tree boa for starters there. They have simular husbandry to the ETB's but are a bit more forgiving if you make a mistake.

I second what green_man said. BCI's are easy to care for and are a great intro-boa, esp if you are looking for something bigger without getting too big. Like he said, their husbandry is almost exactly like a bp's except for the amount of cage space. You will probably need, at minimum ( usually bigger than this though ), a 4'x2' enclosure for a fully growed BCI.

Aboreals are a bit more challenging. They have the reputation of being very nippy ( this is not always the case ), and require some specific temps and humidity.

I would also say a bci. If you're jumping from a bp then a red tail would be the easiest transition for you. Not much to learn or change, husbandry wise. Just more room, as has been said.
I've thought about an arboreal species in the past, but after looking into it, thought twice about it. Their husbandry is still a bit more advanced for me. :)