A bit of advice required again peeps

In process of my i7 build and have a little problem with barb fittings.

Using 7/16 tubing on G1/4 1/2 tails.

I ordered these EK barbs and they fit, but do not seal as O Ring does not compress when tightened down on the following components:

XSPC Full Cover Razor GTX280 - Acetal

Swiftech MCR320-QP

Would these be better or even these?

Any help appreciated