I Think Spike's is Playing Me

[Vlad the Impaler]

More rail options

That's a Daniel Defense Omega rail. It's the only free float rail that you do't have to remove the FSB to install.

I've been looking at Spikes and found this thread.

One more free float option for not removing the FSB is Vltor CASV.
The monolithic rail carries it and it separates (M203 capable) so the FS can stay on.

 

[Bradis Guns]

Do these have the select fire markings? Also what would be the price for a complete lower with ambi safety?

They do not have the select-fire markings. Cost for one complete with an ambi safety would depend on what parts kit you wanted to use for the build-up, and what your definition of "complete" is (i.e. buttstock assembly or no).