Tradeoffs for creating higher order butterworth filters
To get a steeper rolloff, I am thinking about cascading 2 or more of these 4th order filters and create higher order ones.


Cascading two 4th order Butterworth filters does not give you an 8th-order Butterworth filter.

If you want the benefits of a Butterworth filter (maximum passband flatness), then you should go back and design an 8th-order Butterworth filter.


  Is that ok or are there any tradeoffs for doing so, other than the increased complexity of the circuit? Will the PCB layout difficulty increase?


More components means more PCB area. 

As another answer points out, more stages means more noise.


  Is using a Chebyschev optimization instead of Butterworth a better idea for my use case?


A Chebychev filter will let you trade off passband ripple for steeper roll-off. Presumably in the limit that you specify minimum ripple you will just get the Butterworth filter (but I'm not 100% sure on this point).

Only you can decide what is the correct balance between roll-off and ripple for your application. 


  Are there any better approaches


If you are targeting some well known application where there are many customers who need the same type of filter, there may be a drop-in filter component available to suit your needs. This could be a passive resonant structure that can act as a high-order filter in very little board area, and with no noise sources. The suitable technology and availability will depend on your exact center frequency and pass-band requirements.