New boa owner questions

Hi!(:
I currently have 2 ball pythons and a corn snake and all have done very well. I'm ready for a little bit bigger snake. I would love a red tail boa. I have done tons of research,but have a question. How big do the males get? I've read different things. I'm wanting a boa that stays in the 6ft range, maybe 7ft. I think i can handle a big snake in general, but don't have the space for an 8-10ft snake. I was looking into the Hog Island Boas, but i dont think those are a good option. Knowing that they're hard to find and most aren't purebred. Would a male red tail boa be a good option for me, or is there another boa i should look into? Thank you (:

Look into the pure dwarf localities if you want a BCI that will stay on the smaller side. Tarahumaras are the tiniest, the females top out at 5' and males at 3.5-4'. There are other localities that are slightly larger but you have to make sure they're from pure lines and not crosses.

This is a very good question with many answers. The long and short of it (see what i did there?:D) is that males are typically smaller, but some do get big. All boas grow for their entire lives, so their "adult" size at at 5 or 6 years old is not going to be the same at 10 or 12 years. First you have to pick a subspecies, for you boa imperator (common boa) will be better than boa constrictor (true red-tail) as BC's tend to get bigger. Among BI's, those from Central America are the smallest, but they vary between localities. In General, Central American boas max out around 6ft, with males even smaller, but this is a generalization . That being said, you may want a columbian BI, they are more likely to find 7 feet, especially the females who also tend to be heavier bodied. Dumerils Boas are also a very interesting option -- they tend to be a bit shorter than BI's but heavier bodied as they don't have arboreal tendencies. I've heard they have really great temperaments.
I (and many others) highly recommend The Complete Boa Constrictor by Vincent Russo; not only is it a definitive guide to care and husbandry, but his knowledge of locality and subspecific traits is invaluable.
My limited experience is that i wanted a snake but was nervous about size so i got a male Central American, and although i LOVE my little buddy, now i am pining for something bigger.

Dumerils do have great temperaments - I have several - but they can grow pretty big and with that thick heavy body they are a lot stronger than a BCI or BRB of the same length.