SpaderTanker

FrozenQ has some at around $100. http://www.frozencpu.com/search.html?mv_profile=keyword_search&mv_session_id=t65i9wj4&searchspec=FrozenQ+helix&go.x=0&go.y=0
 
I'd personally never skimp on reservoir quality. A bad O-ring or a minute crack can cost you thousands. You could always get a decent res from EK or so and add stuff in it. Caps with LEDs on them or these coils (which don't work, mind you)