應該是when do we present the project for you 定用 to you?

假如是直接問對方是主持人/比賽主辦機構/老師等對方(要求的"功課"/"習作")的話，你應該寫為：

When would you like us to present the project to you?

所以就客觀中立的文法而言，應該用to you.

不過，假如你的project是你的公司設計或對方是"客戶"，你不是想表達"交功課"，而是尊重對方，期望對方是以看"表演"的心理來看你的project presentation; 那麼你便可以寫/講成：

When would you like us to present the project for you?

to you

for you