Combining the systems is probably a good idea unless you expect to split the house again. You might want to consider an indirect WH when you get a little money in hand, much more efficient than a typical standalone tank, and faster recovery, too. 93/112=~83%, so not all that much to gain on a new one unless it is also able to modulate. A modulating, condensing boiler is generally designed to cold start, and makes use of an indirect more efficient since during the summer, it only needs to turn on when you need to reheat the WH tank, not stay on, when you have little need to space heat. Mine generally only turns on once a day during the summer, after morning showers unless I'm doing laundry.