Yes, artificial rocks are nice in shape, in fact very nice.
The advantage is that they are very nature looking structure but also free of unwanted natural pest.
But you need to beware of the type of artificial rocks (AR) which you are getting, are those AR hollows inside or solid. If the AR are solid type which is heavy enough to submerge in salt water it will be better. If the AR is hollow inside, then the only way for it to be place inside the tank is to allow water to fill up the AR so that it can submerge. The potential problem with a hollow AR is that the water that is trap inside the AR does not get circulated, which in turns becomes a potential nitrate factory.
If you are gonna be keeping sensitive corals like SPS, i would urge you to consider using a solid AR instead of a hollow type AR. This will eliminate potential nutrient problems in the future.
As for the housing of bacterial, this can be solve by having either a good quality ceremic chips and / or sand bed in your sump tank. Of course, if you have some LR in your main tank, that would be even better.
Perhaps a good mix of LR and AR ( try to get the solid structure type) would be ideal.