I would run 2x 1/2" hardline or RG11 from the utility building to the house and barn, as well as 25 or 50 pair tel cable, and 4 or 6 strands of Multimode fiber. land everything on a backboard.
Now you have options.. You can put the cable modem out in the utility building, and use media converters and/or a small switch to feed the net in both directions, or you could put it in the utility room in the house, and not put any active devices in the utility building, and just cross-patch the fiber.
ditto for telephone.. especially if they decide to put in a key system.
Make sure you have enough telephone pairs to be able to cross connect one building to the other with spares for expansion and incoming lines.
If you earch on CDW.com, you can find a bunch of small ethernet switches that have 1 or 2 fiber ports, or can take fiber modules. Depending on if they want 100mbit or gigabit, speed, and managed or unmanaged switches, these can be cheaper than media converters.
Check with POCO, and see what it would take to get permission to run a private cable along their pole line, and price out having 1/2" or 3/4" hardline installed along that run.. you could then have CATV demarc at the pole at the far end of the run (just jumper between hardline runs).
