Here's what I would do: Plug your arrow (the arrow that shoots like a dart) and bow specs into Stu Miller's calculator. Keep playing with his calculator until you get the bow and arrow to match up.
For example, you are certain about the arrow itself, but not the bow draw weight. So, play with that. Try to make sure of your personal draw weight. Plug that stuff in. Doesn't cost you anything.
Then figure your personal form factor so that the bow dynamic spine calculation matches the arrow calculation.
Once you are there, save it, and use that as a "go-by." So, you now can examine different arrows, lenght, and head weight until you come up with a heavier arrow. This will save lots of buying and lots of experimenting. Once you get close with an acceptable arrow, you can then fine tune that and make sure it flies well in the real world.
If that's what you want.
Otherwise, shoot what's working now.