X: 1% Trainers / Supporters / Stadiums / Energy: 37% Items: 13% Supporters: 10% Tools: 3% Ace Spec: 1% Stadiums: 5% Special Energy: 5% If you're going to pick a different number of cards, I would go with ones that are divisible by 6, 8, 10, and 12
About finding rare cards, there may be some trick out there that hasn't been found yet or may be added in the future
Each deck set includes 1 ready-to-play deck of 100 Magic cards (2 Traditional Foil Legendary Creature cards, 98 nonfoil cards), a 2-card Collector Booster Sample Pack (contains 1 Traditional Foil or nonfoil special treatment card of rarity Rare or higher and 1 Traditional Foil Borderless Uncommon card), 1 foil-etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art), 10 double-sided tokens, 1 deck box (can hold 100 sleeved cards), 1 Life Wheel, 1 strategy insert, and 1 reference card
Research Thief Five mana, even with flash, is rough