2 Air stone questions

Is there any way to get my ceramic air stones / air discs to lie down flat?
When I had gravel in my tank the only way I could do it was to bury them (which
I know you're not supposed to do), and now that I don't they're each nearly
vertical.

I have two 4" air discs, but bubbles only come out of about 30% of them, so I
think I need a bigger air pump. Anyone have a recommendation for one that's
powerful enough for both, and runs quietly?


Cheers