Definitely go for the Royal Highlander; the jump jets makes all the difference on a 3/5 chassis. If you're a 3/5 'Mech and you commit to a fight, you have to win it, because you don't have the tactical maneuverability to prevent any other design short of an Urbanmech from chasing you down. But if you've got jump jets, you can at least try to use intervening terrain to slow your pursuers down enough to make a fighting retreat.