Upgrading tank...help me pick please

[CD_Scapes]

Hello, I have a UNS 45a (9 gallon AIO) and it’s going great, I love the tank but not so much on the dimensions and how the tank doesn’t really skim that well. I am thinking in the next year or so I will upgrade the tank to either an IM 14 or IM 20 drop off. Leaning more to the drop off as it’s more water and the drop off just looks cool, only problem is it’s a “concept” from IM and I’ve seen the portrait style is already discontinued so idk how much longer the 20 drop off will be around. Any other tank ideas under 20 gallons? Trying to make the upgrade under $700, I already got lights and an ATO from my other tank so I might just move those when upgrading. Light possible an AI prime HD?
pic is current tank

 

[ClearLife]

Corallife BIO Cube 16 worth a look.

 

[CD_Scapes]

Corallife BIO Cube 16 worth a look.

I would but the rounded corners are not my favorite. I used to have the 29 and it was a pain to clean the corners