Re: where can I get bulbs?
Dave if I get you well , you want use your existing fixture and put higher tube in it , if so here the bad news :
when you put a higher wattage tube, you need to make sure the ballast will support it, I may be wrong but I never see a 18” 40 watts tube, what you need is go with more expensive tube like VHO, with the expensive ballast than go with it , or add more tube, again resulting in changing the ballast. You have also the compact tube fixture. But even the smallest one will give you 65 W
But all those solution will cost a lot of $$$$$.