That Urbanmech is going to hurt you. I would seriously consider swapping it out. If you are dead set on using it then roll with it, but the movement profile is going to mean its left in the dust by even the Catapult.... If you are dead set on using the Urbie then I would run another Heavy / Assault mech as the standard 3025 lance is 1 Heavy, 2 Mediums and a Light. So going with two lights, you are going to want to frontload your forces with two Heavies to round the lance out. Otherwise against other lances (particularly ones that include fast Hard hitting mediums) you are going to fold up like a cheap suit. The Wasp is the only mech with enough movement to scout or spot for indirect fire and the Urbanmech doesn't have the armor to hold up in much of a fight. It also doesn't have enough mobility to excel where light designs should. So if the Urbie must be included you need a tough stalwart mech to be the target, soak up enemy fire and dish it back out while your other forces engage enemies who have their attention turned. Many others have suggested the Vindicator which is a tough as nails medium that Jumps (which you want since the rest of your forces do). The Vindicator is great and will punch above its weight, but you need a heavier mech with the 3 lancemates you proposed. Since you have a ton of Vindicators waiting to go, I'd swap one for the Urbanmech and add another.
So I would recommend the following:
Catapult
Vindicator
Vindicator
Wasp
If you absolutely have to Keep the Urbanmech.....
Catapult
Victor
Urbanmech
Wasp
The Catapult has good long range coverage with its LRM's and you can't really afford to sink your other mechs tonnage into an LRM boat since you don't have the luxury (So a Crusader is a bad move from this standpoint although the Cappie Crusader is a great variant). Your Catapult can cover for a heavier unit with more armor that can close and make your enemys day bad (The Victor). They won't be shooting at your Urbie because they will be more worried about the Victor. Also it has a highly Capellan Flair and everything Jumps. Some of the other suggestions, Warhammer / Marauder etc are not bad and are solid choices but don't Jump and offer similar or less armor to the Victor for the same BV. That puts it only about 300 more BV than a Vindicator and provides you much more staying power for games. So you can still put good gunners on the mechs that matter and meet 4K BV points.
A lot of Players still play at 4k, most have moved to 6k (in my experience) but in 3025 games tonnage is equally used. Its really the only era where tonnage works. A lot of players use the standard 240 ton tournament weight for a lance or go light with 220 or 225. So looking at the tonnage the Victor is going to get you closer to "average" than anything sub 75 tons. I think its worth it.
