the only celica-specific splitter that i know of is the apr gt300 splitter which should also look good with the veilside ff (veilside II) kit you mentioned.
buddyclub also makes several splitters, but they are not specific to the celica and personally i'm not a fan of universal aeroydynamic products.
you can buy the splitter right here at the ecelica store (as well as view more pictures of it):
https://celicahobby.com/catalog/product_info.php?cPath=34_43&products_id=141
