As for £21 value bundle...
PLUS your name (or a name of your choosing) on a major character in the book. Someone important to the story, someone who does well in the story, someone you'll be rooting for. Again, names that seem rude or silly will need proof that they're genuine.
As for £45 value bundle...
PLUS your choice of situation for one story. You've picked the name, now decide where your character is and how the story should start. Give me a now-get-out-of-that and I'll give you a cheerful, heart-warming yet thought-provoking resolution.
Anything too horrible or insufficiently bolted down to the real world will be returned for amendment. But I'm sure we'll be able to agree on something.
Well, we can all dream, can't we? If you stump up the whole funding target in one lump, you can have the £126 reward (with your dedication above the other guy's) and there will be an eleventh story where you have as much creative control as you like - as long as there's nothing obscene, libellous or really icky. I'll also follow you on Twitter, be your friend on Facebook and send you a Christmas card (at Christmas, obviously). And there's no excess shipping fee if you're outside the UK.
The Wedding Special. Similar to the £75 reward but, for this one, give me the names of the happy couple and two of their friends. I'll construct a wedding-themed adventure which ends happily ever after for the couple. The friends could be thwarted (if you like) - but nothing involving injury of any kind. This will NOT include a paperback or ebook of "They All Die At The End" (not appropriate for a wedding?) unless specifically requested (no extra charge).
As for £75 reward... PLUS your name in the dedication at the beginning of the book. Actually, more than your name. Give me a sentence and, as long as it's not woefully inappropriate, it goes in. And really long sentences count as woefully inappropriate, by the way. If you're reasonable this will be easy to agree on.