Of the options you are considering, I'd think option 2 makes more sense, and 4-5 feet of conduit - in most cases the conduit will just be continuous from the junction box right through the wall, no particular fuss "as it enters the house" - Come down the wall, put on an LB, drill a hole in the wall, insert conduit, connect to junction box, connect to LB; done. This might be aided by drilling at least a pilot hole from the inside out to make lining it all up easier. Also pick up some duct seal (gray putty, in the electrical aisle) to pack the wires as they leave the LB.
If the wires are entering via an existing conduit, you just need to connect a new conduit to the box that conduit terminates in, and your junction box.
EMT or PVC is six on the one hand, half a dozen the other. I use metal aboveground and PVC below, mostly.
There should be no problem doing what you want, as long as all the conductors and overcurrent devices are sized properly. As per National Electrical Code, you'll size the equipment grounding conductor (EGC) based on the largest overcurrent device used. Which means the EGC will likely be sized based on the size of the breaker protecting the 240 volt circuit.
National Electrical Code 2014
Chapter 2 Wiring and Protection
Article 250 Grounding and Bonding
250.122 Size of Equipment Grounding Conductors.
(C) Multiple Circuits. Where a single equipment grounding
conductor is run with multiple circuits in the same
raceway, cable, or cable tray, it shall be sized for the largest
overcurrent device protecting conductors in the raceway,
cable, or cable tray. Equipment grounding conductors installed
in cable trays shall meet the minimum requirements
of 392.10(B)(l)(c).
Best Answer
"Direct burial" means that the cable is rated to be in direct contact with the ground and keep the ground water away from the wires inside. It does not mean that it is only to be used in direct contact with dirt.
Feel free to wire your whole house with direct burial cable if you'd like, just be prepared to pay through the nose for it. (Just be sure to use wire also designated RHH/RHW-2 to do this - it's flame retardant and approved for indoor use. It must be used even if running in conduit.)
Long way of saying "yes", feel free to put it in a conduit as it comes out of the ground and makes its run to wherever you're terminating it. Actually, unless it's coming directly into a building, you'll be required by code to run it in conduit to protect it. Just make sure that your outdoor junction box is properly watertight.