I will try and explain some things here.

808 kicks tend to have less 'tops' or click or whatever than 909 kicks.
That's why 808 kicks lend themselves to be used for basslines. Especially in drum and bass that's a common technique to generate the 'sub' - part of the bassline. They also exhibit a longer decay time than other kicks. More the slowly decaying boom-type of kick. They are also easily tunable.

They can, as DB said, be sidechained to the 909 kick so they duck in volume when the 909 kick triggers and go up inbetween. This + adding an additional 808 inbetween the normal ones will help to emphasize the typical 'oompa'-character common of lots of schranz (sorry), making it pump nicely and subby in order to provide a solid and driving foundation for the rest of the tune.

Instead of using 808 kicks, possibly with an extra bass boost in the sub region you could use synths or lowpassed percussive loops, that have say bongos, congas, toms in them to provide the needed 'rumble'. And sidechain compress them accordingly.

It is important to get the kick - bass relationship right to lay a solid foundation. If this part doesn't work the entire track is likely to fall apart.

You don't build houses on sand

Hope this helps a little.