Now that you know I won't be trying to talk you out of a bass amp...
IF I wanted the "power" and loudness of an amp and my DAW couldn't
handle it OR there was a need for an amp because another was involved and a single DAW
couldn't cover both needs I would;
Get a power amp and a full range speaker cab(s)- (probably stereo set-up) and use my DAW.
My reasons are the versatility of software.
If you take my Guitar Rig 5 thread into consideration you'll understand that with something
I already have there is no way I could or would purchase all the equipment to do what it already does.
I good power amp and two good full range cabinets for use other than mixing sure adds a lot
of flexibility to the DAW. ( and may save a lot of money not buying equipment that is really specific for a single function)
Of course one needs an interface with multiple outs.