"We all know a single engine like B3 is better for sling but we have to meet the clients requirements and if they require a light twin"
Then tell the client that requiring the twin is not bright. If a twin has to make 2 trips instead of 1 then there is more exposure, 4 engine trips and 2 times the exposure of other critical components to achieve the same thing payload transfer.
Twin mania needs to tone down.
The OEI performance of a single is not as bad as people make out, it just means you have to land imediately, its rare and the outcome is also rarely bad enough to justify the downside of the twin. (and we have already seen that 2 engines does not make the need to land immediately 1x10-9 rare, nonsense untrue maths)
anyway if you really had to be in a twin (for some reason) the 355n is a good machine, i do agree