Need something that will dig deep in the sub bass and have enough rumble to satisfy my basshead needs
You might wanna check the Monster isport immersion.
The bassiest Iem that I have is the Meelectronics S6P, the memory wire can be problematic for some though, not my case. For $28 you can't go wrong.
About the monster they check all your requests
Also you can wash them or take a shower with them.
The only draw back is some inconstancy with QC, some of them are durable and some of them not so...but the majority of people had no issue with them and they seem extremely satisfied with them for their purpose.
So as long as you order them from a reputable site with good costumer service you should be OK.
Also you should check the Meelec M6 (though I am not sure they have more bass than the Monster|),
As well as the Sennheiser CX 685 Adidas Sports (also less bass than the monster)
Don't go with the Monster!!
I have the Monster iSport Livestrong, which I bought for treadmill use, and I actually don't like them a bit. Compared to my UE 700, Phiaton PS 20 and even my Sony MDR-ED12LP their sound is really sharp and have no bass. Even worse, after awhile the plastic pieces that are supposed to keep them in the ear start to get soft and they keep falling. I still don't know which phones to buy to replace them.