40 Gallon Breeder...Mopani Wood?

Hey guys--I just recently broke down my 40 breeder community tank. It was a rush job when I moved into a new place and I was never satisfied with it. I am currently re-scaping it and trying to decide what to do. This will ultimately be heavily planted and house Pearl Gouramis, zebra danios, and who knows what else. Also likely to get a nicer light (maybe a Chihiros).

I had some nice gravel, aquasoil, and sand, so I laid down a substrate layer (aquasoil in rust-proof bags capped with a mix of gravel and sand).

As far as the hardscape...I was thinking of using the big piece of Mopani wood I've held onto for almost two decades now. But I've never used it in an aquarium before, so I have some questions: will it likely create "gunk" that needs to be cleaned off of it? Will it sink easily/can I secure it enough so that it doesn't float? What kind of rocks would you use with Mopani?

Here are some pics of the tank so far, and how I am playing around with the Mopani so far. Curious to hear your thoughts/suggestions for how to use this piece!

 

I prefer the first image 4317, not 4321. I would probably place the piece a bit more to the right, so it becomes a little more asymmetrical.

Add stones on top of the wood for a while to ensure it doesn't float. I think I would add a few stones sparsely close to where the wood touches the sand.

Here's a nice example: 55 gallon biotope journal | Freshwater Aquarium Journals Forum
Which still has a few stones on top of the wood for the same purpose.

The wood probably creates some "gunk". Which is very beneficial to your tank. It will go away over time. Just be patient.

 

Wow what a cool looking peice of wood! Usually you need to hold it down for a while until it gets water logged, mine took a few months to be heaving enough, until then we just buried it in the gravel to keep it down. It might be a white funky film on it but it does go away and fish like to eat it, atleast mine did

 

That is going to make for a real showstopper of a tank! I like the first image 4317 best.

 

That is a awesome piece of wood, very nice. I probably have wierd taste but wonder what 4321 would look like with some plants placed strategically. Might be interesting