A plush Mayor. Obviously. Comfot him when he nearly falls into lava! Sleep sound beneath his gaze of civic responsibilities! Also, he's topical what with the whole "no kings" thing.

I'd love it if they did a series of character sticker sheets. With the huge cast of characters and the sheer number of redesigns, they'd never run out of material. Digital Circus has them, Vast Error has them, so why not Homestuck? (I count stickers as "interior decoration" for budget purposes, so I can splash out on them.)

I'm a board game nerd, so I second the Cherub chess set. Here's a leftfield idea: a Midnight Crew v/s Felt board game. It'd be an asymetric war game, like Hnefetafl or Thud, only with a special move for each piece.