I think that sounds like a good idea. Axies love to lounge in plants, and hide under caves, so that sounds like a well-rounded tank for one! There are a lot of good threads in this section of the forum about aquascaping tanks that have good lists of plants. Basically, anything that is alright with low light and low temperature will be good.
What I've been doing to get ready for my tank is just flip through these forums and make a list of plant species that people recommend and say work for them. That way, when you go to your store to buy them, you can have a list to guide you and can look for plants on that list that appeal to you and the idea you have for your tank. It might be nice to get a variety of heights in the plants, so you can have tall ones in the back and shorter ones in the front for a nice layered look.
You're on the right track too about the plants lessening the output from your filter, so the current isn't so strong. If the plants are in front of the filter, they can calm the current a bit so your axie doesn't get too stressed.
As for hides, I find the best ones are often home-made. If you can find some aquarium-safe clear 100% silicone, you can glue stones, bricks, pipes, whatever together to create a custom hide. I see a lot with a flat slate top with river rock sides to hold it up. Many pet-store hides are too small for full-grown axolotls, so you often have to make your own. It might be neat to combine a piece of driftwood with some stone to create a really neat looking cave.
Also, it's usually good to have more than one hide per axolotl, so if you have the room, try to include two. Although if he REALLY ends up liking the plants, that could probably count as one anyway.
Well, I hope this helped a bit! I'm still setting up for my axolotl, so I've been spending TONS of time on here doing research, so feel free to message me about stuff, and I hope you eventually post pics of your tank so we can all see what you did with it! The best advice I can give is to just poke around this site, read lots of threads, and listen to all these awesome axolotls owners that know their stuff.
Sorry about my essay! LOL
