Hey Nature Boy good to see it's working out for you.
About your high glycemic carb source you can buy either maltodextrin or dextrose. I buy dextrose from supplementdirect, it's extremely cheap @ 11pounds for $10. Post workout shake should consist of no fats or fibers, and i use 50g whey and 50-70g dextrose. Works great for me. If bulking make sure you eat 1 hour after.