PSA has graded a total of six Pikachu Illustrator Pokemon cards
I feel like this is one of the most well-realized precon decks ever out of the box, so you dont necessarily need to change 30% of the cards straight away even if I told you to jam a few games, talk with your group about the power level you want, and then decide where you want to land on the scale between AFR Set Constructed Venture Tribal and Legacy Reanimator Combo

Lets see what you can find in March of the Machine set boosters as an example: 1 Multiverse Legends card At least 1 battle card 1 traditional foil/foil-etched card of any rarity including Multiverse Legends in traditional foil and the foil-etched treatment 2 wildcards of any rarity (opportunity to open MOM Commander cards, Jumpstart booster rares, or Multiverse Legends) 1 basic land/full-art harbinger basic land in traditional foil or non-foil 1 double-faced Phyrexian common/uncommon 2 connected uncommons 2 connected commons 1 art card 1 token/ad card, double-faced Helper card, or The List card Id look for old set boosters if Limited play isnt your jam and youre buying cards to increase your collection
1:4 packs
Collector boosters take that buzz up a notch
Weirdest Reserved List Inclusion Farmstead There arent actually that many cards from the early base sets on the list, so my choice of bad rares was pretty limited