Best place for body panels

[Chyrosolite]

Hi, after poking around my newly purcahsed 325ise, i found the nearside rear lower arch/sill was mostly made from fibreglass and filler! so i plan to cut it out and weld in a repair panel.

Now where is the best place to get panels from? I know of places around where i live but are pricey, also ive checked

Sel-imperial body panels

and a few other places!

Thanks