Honestly, I'd go with a bunch of Smalls. Three ER Smalls in each arm, two SPLs in each torso. But then, that's because I'm lazy and it'd still match the mini. ;)
Then I'd add a Bloodhound, and a half ton of Cargo ala the Wulfen Prime for 'extended operations'. A single MechWarrior can function for a long time in the field with 345 kg of rations (for "quarters" on a spacecraft, it's 5 kg per person per day. Since a 'Mech can be exited, and there's no need to recycle air or water [see rest of list], that should work for a few months' worth), 105 kg of spare parts (three months), a portable water purifier, and some scout equipment.