ya honestly after using a few egyptians, mod, small phunnel, and vortex, i found the vortex to be the best for everything including tangiers, the phunnel with a mod is ok, i havent tried the new mini phunnels but the idea is good and frankly even a small tangiers i feel wastes a lot of tobacco.
for holes i use a tooth pick (not the biggest holes i can make with it though) and do rings of 16,12,8 1(the 1 only on egyptians and on the phunnel and vortex i keep them more to the out side. eric of tangiers or maybe hookah john (cant remember who) smoked a phunnel bowl with only holes on half of it and no holes on the other side and the only thing it did was prevent ash on the side w/o holes. honestly ash on the tobacco is not an issue and is totally normal
as to the headaches, you might be chaining too much, might not be drinking/eating enough, might be getting co2, might just not agree with some of the stuff in the tobaccos you are smoking. i would try some nats and see if that helps and if your not drinking much do that and maybe lighten up on how fast you smoke
hope my glass rant didnt come across as prickish in any way, i just am majoring in craft/material studies (BFA) and concentrating in glass blowing and metalsmithing so i am kinda a materials nerd