Thanks for posting about it Wiseman, glad you enjoy it ^^
Allow me to reply to your suggestions:
@Wiseman, as our website started pretty late, we already had a tough job covering all the earlier G4 merch. At the moment it's harder and harder to find stock images of older gens and it would take it a lot of effort and asking around before we could even have a decent database of older gens. I personally think that there are plenty of sites (like Strawberry Reef) who've covered older gens perfectly (but true, they don't have checklists).
@Violet, not a bad idea! At the moment you can see your own checklist/wishlist boxes when you browse someone's wishlist (so you already see what you own of his/her wishlist), but we could make it a bit easier to spot with a gift icon or something