I would start by saying that you should do as much homework and research on them as possible before jumping in. They are for the more experienced owners, not that it can't be done, but you will need to invest in the proper caging and set up. A simple exo terra/heat lamp and spray bottle will not work well for long before the animal stresses out.
if the only experience you have is with the 4 snakes you mentioned !!! maybe look into an easier to care for arboreal snake like the amazon tree boa?? they are more forgiving about the parameters, this would give you experience needed and prevent a bad experience or worst !! cause the snakes death..
going with a ETB or Basin
If you find CB animals, temperment is not too bad, but these are not hands on animals, they are more of a show case snake that you leave ALONE, they can be handled, i have some that i can trust 100%, others not so much
but for their health and safety they are best left alone.. stress can cause them to regurge,or stop eating,get a RI or bite you and brake a tooth which in turn can cause an infection that can kill the snake..
feeding is not the same as with other snakes, they have a very slow metabolism, an adult will eat once every 3-4 weeks a rat no bigger than it's widdest part of it's body, you feed 3 meals and wait for bowel movement.. feed too much , they will get fat, un-healthy and can regurge OR proplaps..
a neotate (baby) eats every 7-10 days and a sub adult 10-14+ days
humidity and heat with a good heat gradiant in the cage is a must..
hot spot 82ish MAX 85 at the probe, cold spot 72/75
humidity never lower than 60% or if so for a very short time, spray to get 90% and let it drop to 60% over 24h period.
ventilation is key.
I could go on and on
but to see about available BASINS look for Steve volk or Ed Marino in the USA, there are others but these two i know, in fact i just got two basins from steve a few months ago
price wise, you can find emerald tree boas of the northern type between 250$- 750$ in the USA, lower prices are usually WC which i would suggest you stay away from.. but a good price for a CB is in the 350-450$ range and can be found
the basins will range between 1750$-12/15000$ it all depends on the stripe and bloodlines..
I surely missed giving some important info but this is a good chunk of it and should give you a good idea what you're getting into
i"ve been keeping them for years and by far they are my favorite snakes.. seeing the live little red babies come is just amazing, but a lot of work and time needs to go into them,
best of luck