Question: I've checked a number of the other questions but not finding the specific answer I need. 

I'm wiring a 100 AMP garage sub-panel from a 200 AMP main in my house. I plan to install a 100 AMP circuit breaker in the house panel. The run to the garage, lug to lug is ~65' and I have to bury the cable to meet code and am going to put it in Sched 40 conduit. 

I'm thinking I can use 1/0-1/0-1/0-4 AL but since it needs to go underground am confused about SER vs MHF and hoping I can find a solution that doesn't require changing cable to go from underground outside to inside the house and garage. The NEC chart isn't particularly helpful to me. 

Also, what is my option for copper instead?

Answer: 
Your options are a minimum of #1 aluminum or #3 copper.

Since it's only 65 feet I wouldn't upsize it for voltage drop.

You don't need service entrance or direct burial type cable if you are running conduit underground you can use type THWN wire. Individual wires not cable. If you don't want to run conduit you can buy direct burial type wire like You are talking about.

Good luck and stay safe!
Since the entire route is conduit, you want to run this in single-conductor THWN wire. Generally multiconductor cable is less desirable in conduit because it is difficult to wield. 

When laying out conduit, make sure to put pulling points in as many corners as possible. Otherwise the pull can be rather difficult with heavy conductors. 

In any case, you must still use outdoor rated cable, so SER is out of the question. And you must run 4 conductors. (Unless you really want 120-only or 240-only, but you don't.) 

Use aluminum. Yes, really. You may have heard the bad press about copper and aluminum wiring interacting badly and starting house fires. That is due to dissimilar metals corrosion and thermal (expansion) issues; copper lugs do not like aluminum. (The reverse is untrue). Large wires are expected to be aluminum because copper is rather expensive. As such, the lugs are aluminum. The trouble with Copper is it will have corrosion/thermal issues with the lugs. *Isn't that what we're trying to avoid?*