I vote Filco
Thought you'd go for KUL or something
KUL is cherry stabs, and the MX blue version isn't out yet
Oooo true I completely forgot the main point here was costar stabs, ignore me.
Instead I'll direct you to my original post which you don't have to ignore. Filco/QFR 
But does the QRF-i have Costars? I've seen a few reviewers saying it does, and some saying it doesn't. But the OEM is Costar, so it should have Costar stabs, right? Or am I missing something?
I believe it has Costar... not sure though.
You said "Doesn't need to light up" so... why not just QFR
Because I can't seem to find the QFR anywhere with Blues from a reputable dealer. Amazon only sells them from third parties. MechanicalKeyboards.com doesn't have them, and I'm not sure of any others that do.
Rapid-I comes with plate mounted cherry stabs. Carter(CM Rep here on GH) mentioned the non-backlit QFR were in shortage at the moment due to switch availability. I'd say WASD might be your best bet for a readily available TKL with costar stabilizers.
That's what I'm probably going to do. $95 for a TKL is not that bad, and I can get a nice blank Ducky keycap set.
And I did clipped my stabs on my KBT Pure Pro and they still just didn't feel right, but I tried my friend's QFR and it was perfect. I didn't have to wait for the switch to pop, it was almost instant.