I don't see any reason why it would not work. Our's came with stand alone furniture. We took out the table and chairs and moved the couch to the other slide out and removed 2 rocker chairs and install a normal house hold style reclining couch. The weight of the couch is probably equal or less than the original couch with kitchen table and 4 chairs, or the 2 rockers and table and chairs. So no problem with the weights.
I don't think there would be that much difference in the weight on the slide, even using the area under the new sofa's for storage (unless you are planning on starting a rock collection (like Lucy in the Long-Long-Trailer).... then you might have a problem with weight.
Keep us posted on your modification. Looks like a great project. And yes .... we don't miss the kitchen table at all. We use small individual tables too.
