I really think that a Brison 5.8 is way too little motor for this purpose and yes, it does have as much, or more, power than a ZDZ80 twin or single. The Brison will turn mid 6's with a 26X10 prop.

I would recommend you find a deal on a good used 3W-120 or ZDZ120, as I think that is the minimum engine you should run on this.

I have a new ZDZ 120 that is going to be for sale that is a bit out of your range, but it gives you an idea what you could do for just a little more money. I don't want to post the price here and appear that I'm trying to sell it in this forum, but write me if you're interested on what it is going to be on sale for.

BTW, remember that a biplane has considerably more drag than a monoplane and requires more power for any given size...of course this doesn't factor into it for hovering, but it does for most any other vertical maneuver.