Rounding up supplies and looking for ideas of what too add, all services buried.
Here is what I have so far:
1) 2-2-2-4AL MH feed in 2" PVC conduit
As Wylie alluded to, there's no way to know if this will be adequate until and unless we know the loads you're planning to run from it. But FWIW, given the 90-foot (one-way) distance you later mentioned, that should be good for up to about 125 Amps; if we presume another 10 feet on each end to account for the vertical segments and similar, make that about 100 Amps.
2) 1/2" direct bury natural gas line
3) 3/4" PEX water line
Not my wheelhouse.
What kinds of cable would I need for cable TV, computer and intercom?
RG6 for cable but is there a direct bury difference?
RG-6 will likely be adequate for the TV feed; but if you want to keep signal losses to the absolute minimum, go with RG-11.
The computer will require Ethernet (i.e., CAT-5/CAT-5e/CAT-6/CAT-6A), unless you plan to get by on WiFi (which I do NOT recommend, particularly over that distance). Even presuming conduit, I would use outdoor-rated cable, such as:
http://www.monoprice.com/Product?p_id=8115
This will depend on the intercom. Check it's specs to see what it wants. But if CAT-5 will work, so too will CAT-6; so you can simply use more of that same spool cited above (but of course, mark it at each end when you do the pull, so you don't get confused later as to which cable is which -- you DON'T want to be cross-connecting these very different things!).
What is the distance you are running? Do you have cable internet with a cable modem in the house? If so, you will need to run a Cat 5 to the garage for the internet.
He'd need that anyway.
Ethernet can only push a signal about 100 meters/328 ft which is primarily why I ask the distance.
He's well within that limit. But unless he goes to CAT-6A (
NOT just CAT-6) cable, he's pushing his luck with respect to 10GBASE-T, if he ever gets around to upgrading to that. Either way, the best thing he can do to avoid future problems is run the Ethernet cable well away from any other lines (i.e., NOT in the same conduit).
You cable also has a limited distance it can push a signal. My house is about 300 aft off the street, and the cable people had to put a booster in the middle of the yard to get the signal to the house.
SOMETHING is not right there. If your cable provider needed a booster amp just to cover a 300-foot run to the house, the signal strength on their main lines is nowhere near adequate. And if that's the case, howinhell are they going to service the next customer down the road?
Cat5e for Ethernet (300' max). It is the most cost effective. Cat6 would be a bit better (more resistant to rough handling) but it is a lot more $$$ !
Not so much any more, now that it has become more common. The example I cited above is pricier than most, and even it is only about $0.15/foot.
Sometimes; not always.
House is about 90' from the road and barn another 90' from house.
Yes, we have cable internet and not DSL.
So 2 Cat5e runs for the cable ethernet, intercom and how about the RG6 in case of a future satellite dish?
You're going to need the RG-6 (or RG-11) for the TV anyway. Once your incoming cable from the street hits the router/interface box supplied by the CableCo, the TV and internet (and 'phone) services run on completely separate lines/networks from there on out. One possible exception: If -- and
ONLY "if" -- you have dedicated VOIP telephone sets (a.k.a. "terminals"), you can run these off your hardwired computer LAN, pretty much anywhere that LAN goes (including to the garage/shop/barn). But the more "normal" setup is to bring the house's conventional ("POTS") telephone wiring together at that above-mentioned router/interface box, and use plain old analog telephone sets from there on out.