I'd suggest DFW-NRT rather than LAX-NRT. Your SWUs will get you into F (assuming upgrade inventory) so why not enjoy a nice long flight? Plus you'll get more miles. Or maybe even DFW-ICN (I forget when that starts)?

Also, LHR-TLV is 2216 miles each way but Jan/Feb isn't the best time of year to visit TLV since it's a beach city.

If you start outside North America as suggested above, you could add a trip to the Caribbean which is very nice all year round.