To be honest I don't use either clomid or nolva as I hate them both because of the side effects, but the research I based the taper on was done using 50mg of clomid per day.
as for carbs on cycle, it really depends what time of day you train at. Best to keep carbs to a minium during the day time prior to training, and then be more liberal following. If you train in the evening, then thats when I would eat most of my carbs. It all comes down to staying insulin sensitive, and maximizing nutrition uptake and utilization.
Im not going to explain this further... but this is the approach I would take. No point in fattening up for the sake of it, if your going to add weight add muscle weight.