For SBST
Alexander Dennis Enviro500

Can be fitted with either with a Cummins ISMe (330hp)
/ISM(335hp) /ISLe (340hp) or a Volvo D9A/D9B (but if fitted with a
Volvo engine, it will be called a B9TL....)
For SMRT:
Mercedes Benz O530G Citaro G (WARNING: Picture will go
boomz)

Can be fitted with a OM457hLA (2 versions, one with 299hp and
the other, 354hp)
Scania K320UB (320hp) with Volgren CR228L bodywork
Scania OmniCity (CN270UB)

Picture from Wikipedia.
Eh, 299hp too weak leh. 354hp better.
Dun dump Scanias into SMRT fleet can? 