I'll start by picking a strategy - I choose to go with the Run, so I want to focus on maneuverability. Four "strategy match" characters (in this case, Runners), two Blockers and two Specialists.
I choose the Thief, the Elf Scout, the Pickpocket and the Prophet as my strategy match characters - they all move 5 or more, and the Prophet has the added bonuses of being able to orient rooms before I reveal them AND being a Magic User. For my Blockers, I'll choose the Troll and the Weapon Master. I'd choose the Undead Dragon, but I'm concerned about running into the Hit strategy, and a dead Dragon is 2 VP. A dead Troll is only one.
For Specialists, I'll include a Mekanork on general principle and a Wizard.
This way, I have eight characters - four theme matches, two Blockers, and two Specialists to support my team. Using the Prophet and the Mekanork gives me a great deal of control over the maze. The Wizard can fly, which enhances my mobility. It also gives me a second Magic User, so I may consider including some Scrolls in my item mix.
The next thing I want is Items. My party is combat-weak, with an average combat value of Pathetic. But I've got two Magic Users.
Given that I'm pursuing the Run, I'll start with at least one Rope. I'm also going to grab a Key - there's no telling what sort of rooms my opponent is going to challenge me with. I think I'll also take an Elven Shield so I can bypass the Falling Rocks squares (if any) which show up in the maze. The Seven-League Boots will allow a character to fly for ten squares, and it fits well with my strategy thus far.
I have two Magic Users, so a Scroll or two wouldn't hurt. Plus, my opponent wouldn't be able to use them without a Magic User - I think the Scroll of Flight would be overkill, but the Scroll of Inversion and Scroll of Confusion both appeal to me.
My only worry is having some of my items falling into my opponent's hands.
Now, to rooms. At some point, I'll be taking photos of the rooms so that I can show them off.
I don't want to give my opponent the chance to animate or create anything that helps him against me. This removes most of the rooms from Créatures Sylvestres, as they have Trees. It eliminates a couple of rooms from Forces of Darkness, as they have Tombs.
I have two Magic Users - it might be worth grabbing the Library room (part of Pair 16) from Fire and Water. The drawback is that the Anti-Magic room which is paired with the Libraries can make my Magic Users (and the Scrolls and the Elven Shield and the Seven League Boots) useless for at least part of the time.
The other two sets of rooms I'm looking at have the Fountain of Youth in them - with no Cleric, I'd like to make sure I can heal if necessary. The rooms I'm looking at are Pair 22 from Mercenaries, and Pair 28 from À feu et à sang. Both rooms have the Fountain of Youth I want. Both Fountains are in difficult positions - Pair 22 has it surrounded by remotely-triggered traps, and Pair 28 has it surrounded by Water.
Both rooms in Pair 22 have the Ultra-Gravity Holes, so no Flying will function in them. They're also covered with Remote Traps that I may not have control over.
Pair 28 is newer, so my opponent may be less familiar with them. They also have Chasms, Water and Small Bridges (which won't impact me, as I have low-Strength characters).
Any of the three pairs will work for me - For this group, I'll choose 16 and 28.
... and, with that, I've assembled a tournament force.