This is not the place to ask for code. But, I will give you some pointers:
a) put a boolean into the gift-collection called “available” and set all to TRUE in Content Manager
b) query collection on ".eq (“available”, true)
c) throw result at repeater and put a button on every row
d) when clicked, collapse repeater and show collapsed form with data (name, etc). Tip: put all fields inside a box and collapse/expand the box, so you do not have to do this for every individual field
e) submit to collection and also update gift item by setting available to false
f) collapse name box, expand repeater and re/query (or, faster, .splice the chosen entry from array), clear repeater array and fill repeater array again with new data.
g)done