engine build

hi, im planning on building an engine soon and i was just wondering what your opinions were about what platforms would be a good build. i dont care what it is because im building the car around the engine. my only criteria are as follows
-400 ish hp
-reliable/dailyable
-relatively cheap base engine (prefer something thats not a very common build
-prefer more than 4 cylinders but not required.
thanks in advance for your opinions/ experiences