Well not all boas get huge... what's your definition of huge? I have two boas, one I would not recommend for a novice - it's rather high maintenance on the care - 80% humidity required, but that's easy enough with the misting system.

He's also a bit snappy. In case you're wondering - I'm referring to Prism. He's my male Brazilian Rainbow Boa. A beautiful snake though. He will max out at 6 feet, and he's just about 5 feet now. His picture is below:


And the other one, she's a female Guyana Red-Tailed Boa, and she's the smallest Red-Tail boa you can get. She will max out around 7 feet in length. That's not all that big if you ask me. I assume you were referring to the ones that get to be over 13 feet. Now THAT's a big snake.

Here's a shot of Youkai:


I used to have a Kenyan Sand Boa years ago, but they're even smaller than corn snakes.

Most of the other ones I'm thinking of are pretty tempramental as far as care goes, and really aren't that great for a beginner - Emerald Tree Boas are really nice. I don't know how long they get though. Anacondas - no way. VERY nasty attitude, and they get ENORMOUS, plus they require standing water in their enclosure.

Dumerils Boa - can be very aggressive, but is tameable - and they stay around 4-7'

Blood Pythons - make sure it's Captive Bred - the wild caught ones are VERY nasty, but CB are docile. This isn't a beginner snake though - you should know something about keeping/handling snakes, and their behaviors before you get this one. Females get to be 4'-6', Males 3'-5', so they're about the same size as a ball python.

Speaking of which - one of my ball pythons just came out of a 6+ month starvation after I took him to the vet TWICE to be force fed. He wouldn't eat ANYTHING. Finicky is definitely an accurate description here.

I'll try to think of more.