I actually made some effort on my part of editing FE9/10 weapons!
They are quite the challenge and they are my first time making an actual weapon icon for the GBA but they were worth it.
Amiti: 
(I think I made the closest imitation of the Amiti)
Florete: 
(Yeah I know, GBA doesn’t have pink but the handle and hilt come close)
Stiletto: 
(Not sure how accurate it looks on shape wise but I did my best)
Tempest Blade: 
(Let me tell ya’ll, I did not made it from scratch)
Venin Edge: 
(Again the palatte color but the hilt and handle works great)
You’re probably wondering, did I made these from scratch? No.
I legit grabbed the FE10 Weapon Icons and just crop out the weapons I wanted, which is what you can see up there. (A bit difficult to get the size of crop right on these weapons but was worth it.)
Resize them to the GBA’s 16x16 size, insert them, save them and by this guide right here http://feuniverse.us/t/basic-weapon-icon-editing-and-insertion/ for me to use the right tools for FE8’s weapon colors. I picked the colors that somewhat matched and inserted them for the Amiti, Florete, Stiletto and Venin Edge (as best as I see fit from the colors given).
Surprisingly, Tempest Blade actually worked just fine minus the little mess of colors it gave off. All I had to do for it was clean off those unnecessary colors and it just works like a charm, so if you like them use them. Course if anybody here who is skilled are welcome to polish up Amiti and the others.