My bad,, I agree a TANK is tough to clean. We have our Royal in one but that was our first snake and we made it work. The plastic caging is a totally different setup. The best part about these boards is the people you find here have the experience to help. I came here and elsewhere and pretty much took in what everybody had to say from caging, to feeding, to size and locality options.
I took close to a years worth of research and really the only possible regret I have is that I didn't get a female. I love my male though. I'll grow him as big as he can get safely without risk to him.
Anyhow, from my perspective, I'd say you should NOT get an adult boa, you should start with a boa that is 6 months to a year old. The cage should be the first priority and go from there.
Lots of time,,, lots of time.
Do it right and enjoy it!!!