Those coming soon packs from Cosmo Cricket (Sarah) and Fancy Pants (PharmD...) would be awesome. They are both very thick quality.
You can always find flowers from Prima (and fab bling!), I like any embellishments from American Crafts, Fancy Pants makes beautiful ribbons and trims. Really I would say you should pick a major manufacturer like the ones mentioned already and go to the shop... when you click on the paper pack you like it will give you a list of the coordinating products in that line and in a lot of cases there is a tab for coordinating cardstock too...sweet! And remember.. If you can mix and match digi like you do (and boy can you!) you can do the same with paper stuff.