If you are debating on what to buy and intend to expand into Gremlins further I would just go ahead and get the Wong Box. Lightning Bugs are pretty good for playing against Arcanists or any armor spam and Mancha Roja is a solid Henchman. I still haven't assembled my Lovely Assistant because I don't really know why you would ever take her as opposed to Old Cranky.
The Lovely Assistant requires an 8, lets you see the top four cards and then put them back on your deck in any order. This is really limiting as you can't discard those in any way. You are much better served by Ol' Cranky's discard to draw combo'd with Winds of Fate on Sammy to get two instances of card cycling. Is this a much higher use of Soulstones? Of course but it doesn't cost you any cards out of hand and let's you build a stronger hand instead of a fixed top deck that requires the use of a moderate 8.
But yes Stuffed Piglets are very worth it, I would consider an auto-take with Wong. You will want a big scary model to put Glowy on, Sammy to carry OOh Glowy, Old Cranky to give defensive buffs to your crew and Stuffed Piglets for activation control and controlled blast targets. IMO those are the base requirements of a good Wong Crew.
For additions, the Taxidermists are pretty nice. They can make more Stuffed Piglets out of the corpses your opponents will be dropping as you blast them to bits and can give pigs Flight on a 5 of Masks which could be pretty clutch in a terrain-heavy board. I would always take at least one vs Ressurs to help mitigate the amount of corpses they use to summon. Even if they kill the Taxidermist he can use Dead Man's Switch to Detonate your stuffed piglets at once in a glorious shower of bacon and explosions. Creative Taxidermy overall is a good box for Wong.