I followed a similar carb cycling program (http://www.bodybuilding.com/fun/par30.htm) with pretty much the same schedule as you mentioned and found the following to work well for me:
No Carb - 25g carbs
Low Carb - 125g carbs
High Carb - 250-300g carbs
You can increase the carbs on the high carb day as I think the program calls for more than 300g but I find I get very lethargic on more than that amount.