My rebar bender is just a couple pieces of pipe. If I can't find it, I'll bring some more.

The other question is what diameter of rebar to use for staking down personal structures- I can't remember what I've used in the past,I think probably 3/8" or 1/2".

How many rebar stakes? Hmm, did your dome come with stakes or some other sort of attachment fixture, or are there loops/attachment points on it for stakes? In that case, just get one piece of rebar per stake or attachment point. If not, then you'd need to figure out how to secure the dome with the rebar, not sure I could say anything intelligent without details of the dome config.

I'd say 2' pieces, beyond that they're so long that it's a pain to pound them in, and worse to get them back out.

If anyone wants to make official kickass way-better-than-bended rebar stakes, let me know:

I use 1/2" rebar, the pre-cut stuff from home depot. I then buy 2" or so metal rings (you can get the zinc plated ones, just weld with *plenty* of ventillation!. Weld them to the rebar, takes only a minute, and voila, better stakes than the bended janky ones! You can tie things to them much easier, and they pull out quite easily too.

Anyone who wants stakes like these, message me and we can arrange a time for you to come to NIMBY to make them. They are so easy and so much better than bent ones. You'll treasure them always :)