Spacing depends on what you're trying to accomplish. If you're trying to make sure a surface is evenly lit then you can use the beam angle of the bulbs, the distance between the ceiling and the lit surface, and a little trigonometry to figure out what spacing makes sense. For example, bulbs with 30-degree beam angles, on an 8' ceiling, could be spaced 51" apart (or closer) and light the floor evenly. If the intent was to light a vanity top, the maximum spacing would be more like 33".

The thing is, this isn't an office building and you don't have to plan lighting to accommodate cubicles that could be moved around down the road. You can afford to arrange fixtures to highlight what you want highlighted, because sinks, tubs and toilets don't typically move around.

The total amount of light these five 35w bulbs would produce is probably a decent guess, but I'm not sure you'll want them pointing straight down as if the floor were their primary targets. Focussed, direct light is likely to seem a little harsh, shadowy and unflattering. Who wants to be in a spotlight when sitting on the toilet? Also, a brightly lit floor and dark walls will make the room feel small and cave-like. I'd be inclined to look for ways to make the light indirect wherever feasible, by bouncing it off walls and ceilings.

Thanks. The lighting will be for general lighting so I am not trying to illuminate anything specific. I bought 3" gimbal lights and I hope to be able to try different combinations of angles until I get the lighting the way I want it. I spaced the lights so that they are away from the toilet and not right in front of the mirror producing glare.