Basically, the maximum strength is 200 with equipment. You will be able to make 20 Strength potions (which is 100 Strength) and get 5 free from apples/eggs. So basically, 95 is all you need to maximize the Strength even without the use of Strength equipment.
If you have 200 Strength and equip the +15 Strength amulet, you get a whooping.. 200 Strength. So there's very little point in saving potions above 90 Strength; you'll be able to get so close to cap regardless, and can just use an item if you want to reach the actual cap (in your case, the non-gear maximum will be 195, then you can just put on a +5 Strength ring, and you're done).
In any case, there's not a huge difference between 190 or 200 Strength, unless you're trying to achieve maximum damage potential just for the sake of it, in which case you can also use a Berserk scroll to get 250 Strength (Berserk is the only way to boost your Strength above 200).