Looking for suitable IS (Y9)

Elder one (speaks and writes native Eng) is from local elite and the younger sibling is already in Renaissance. We plan to move the elder one to Renaissance too but finding the vibes there may not fit the character. What shall we do Any other good options? Failed in GSIS assessment lately, now STC and CDNIS are on the list. If STC, we need to move to the catchment (current ESF catchment is KGV but not in consideration). We are a family of foreign passport holders. Thank you all for the advice.