My Jungle Carpet was a terror when I got her. She bit at anything that came within like 3' of her. I got her tamed down kind of where it was a 50/50 chance I got bit. Took like 4 months and I would handle her about 2-3 times a week. She never really got calm like a boa or bp. From what I was told about Jungles is that they are almost always fairly high strung. I was told if you want a mellow carpet, get either a Bredli or Inland. I was told both of those are pretty laid back and pretty much all babies are a bit jumpy.
With that said, there will be exceptions. My advice is ask the breeder what the temperament is when you buy it. And like you, I like handling my snakes so that's why I'm a boa and retic guy. All 4 of my boas are really laid back even as babies and Caesar the retic is a lounger as well. If he doesn't want to be held, he just tries to climboff my arms, down my leg and to the floor lol. He isn't jumpy or anything.
I'm sure i'll get reamed for it but imo I see carpets kind of like GTPs, more of a display animal than a daily handle animal. Of course there are exceptions to the rule as I've seen guys with GTPs that were as laid back if not more than any of my boas.
I too wanted a lot of different species but I'm being drawn back to boas lol. The only species that really grabs me are retics specifically SD/D crosses as I don't want something over 10'. That's why I'm going to get me the Peruvian BCC and probably a sharp snow female BCI for Rango. That will probably be it for me for a long time. One day I would like to get another carpet but would probably go for a Bredli or Inland.