shell, Frick & Icky are adorable !!! Wishing you the very best of times with them !
Also, I'd hold out to find that 20 long. One will come up for sale soon enough, you may even want to check out Craigs list (or better yet... put it on your Christmas list ! hehee). The 20 high doesn't offer enough swimming room (plus it's hard to clean, having to reach deep down into it) and you'd end up having to replace it down the road, as Frick & Ick get bigger !
I wish you lived near me, I'd give you my old 16high to use temporarily while you wait to find the 20 long ! I have it disassembled and in my fish closet right now.
good luck with the new babies, they are simply adorable !