Re: Reasonable weight for suburito?
They tend to weigh about a kilogram, yeah. There is a thing called a furibo that generally has an octogonal profile that they make weights you can put on.
I know some koryu practitioners who swing ridiculous, Final Fantasy size furibos around, but I really think at some point you're asking for repetetive stress injury. At any rate those are custom made.
I like to practice movement and technique on my own sometimes and it's nice to have the "stretched-out" balance of a standard suburito for that.