OK, my 2cents: it is hard to beat the simplicity and efficiency of a mechanical fan. You already have a mechanical fan, just add a shroud (apparently mostly for your peace of mind!) and forget it. With a mechanical fan, only one thing can go wrong (the fan clutch), electric ones are not so simple...
Sure electric fans work well too, but good ones are expensive, you need sensors, relay, switches, wiring... And contrarily to what someone else said, they are noisy!
Keep it simple, stay mechanical!
