We were trying to come up with a good not so well off mercenary command though, not a top rating Merc unit.
Note that in Battletech, mercenary units are generally only mercenary units because they offer something that local planetary defenses cannot. They don't have to be rich noblemen, or even of middle-class income, but in order for them to get hired they generally need to be strong enough to ward off pirates, which a force of all Scorpions cannot really do. Just look at the average contractors hiring you for proof of this.
With this in mind, I'd strongly suggest you look at units of 25PV upward. At this PV minimum, you'll get fine bricks like the Schrek, whose 8 health means it can tank one shot from even the very biggest guns 3049 has to offer; the Burke, which provides an extra-nasty long range punch; and the Demolisher, a treaded Hunchback if there ever was one.
If speed is more your style, then you can't go wrong in the Drillson, which mixes Hovercraft speed, medium 'mech firepower, and enough health to soak an AS7-D hit, if just barely. If you work with infantry often, consider a Maxim, which offers the same performance with an infantry bay shoved in for good measure, at the expense of 2 inches of movement.
Artillery offers the one avenue where tanks aren't merely roughly equal to their legged brethren, but in fact vastly superior; in 3049 especially, tanks are, in fact, the only vehicles that carry true, area-of-effect artillery systems. The Marksman or Chaparral offer solid options at an affordable price.
In case you wonder why I focus so much on health; 5 damage at any range is a fairly common number for several common units in Alpha Strike, namely the Hunchback 4G. Additionally, most cheaper units, namely those at your price range, will only do 2-3 damage; not exactly a glancing hit, but not enough to 2-shot most of the units above. Or, put simply; because having 6 health means your tanks will actually see more than one battle.
Hope this helps.