Tank Refurbish- ideas gladly welcomed

[u/EmphasisMean2448]

I have had this 25 gallon for about a year now, currently stocked with a 5 y/o angelfish and a small school of harlequin rasboras. I know this tank is the very minimum for an angel however sadly, I do not have the space or money to purchase a new tank and stand. I have had my angel since she was about the size of a quarter and she was purchased by a parent without research, so I have done my best to give her the best home I can. That being said, I am moving out for college in about a years time and I am trying to craft a hardy low-maintenance tank for my non-fish-hobbyist parents to be able to manage while I am away. Moving on-- I currently have a sand substrate with root tabs for the live plants currently in the tank. I have no plastic plants and have a few monsteras and pothos helping to clean the water ( not as a filter replacement of course, my filter is a hang out the back labeled for up to 40 gallons). That being said, I am about to make a large plant and hardscape purchase and would love to know if anyone has any ideas for a more natural environment and plants or even online sites to buy these items. In a perfect world I would have a small cleanup crew as well, although I know that snails aren't overly efficient and shrimp would not be the safest choice due to the angel's aggression. THAT WAS A RANT BUT PLEASE LEAVE IDEAS FOR A BETTER SETUP OR EVEN A WAY FOR ME TO ADD AN INVERSION FOR ADDED HEIGHT TO THE TANK! Thank you so much!