Ducky make some nice ones in PBT but the black ones are, or at least were, thin, if that bothers you.
If all else fails there's always
pimpmykeyboard, as long as you can live with a 2@ key you can get Standard DCS doubleshots with an ISO pack, and if you want to add a splash of colour you could get the mods from that set and the alphas from Midnight as they're the same profile. They're ABS so will go shiny, but they're not going to break on you and doubleshot means the legends won't fade as it's built into the cap.
If you need an enter key while you search drop me a PM and I'll stick one in the post - it won't match the profile of your other caps but better than nothing!