I'm thinking about buying 3x of these
Would it be enough light for the entire room? and good buds?
No not quite enough, but it's not far off factoring in access area. They always say 3x3 but it's a guide, most only cover 2x3 effectively down the length of the bulb. Closed hoods can project a more even spread but you typically have to increase light distance to achieve it.
You may consider putting the plants against the back wall leaving a good 6 inches gap from it and canopy. Use a row of two from left wall to right |=====| like that. How many depends on pot size. You then run 4x your connected hoods over the top with a little room either side for the venting. Those hoods look ok but they are not going to have great over lap yet better penetration over cheap open hoods. 4 over that area would allow you to cover it at a lower height and penetrate better for good mid bud production. That's my opinion, and it should hopefully fit with a little wiggle room. Otherwise yeah, 3 it is ;p.
As you walk into the room you have a 2f walk way along the face of the front row plants. Access to the back plants, you can use some tools/tricks that remove the need for moving pots. This will make the most use of the space and lights while leaving comfortable access, unless your door is in the middle of the side wall ;p.
The space at the front is something you will truly appreciate over time. Again you are totally limited by ventilation, having vented hoods will not out right solve the problem. If it's a basement you'd be fine mostly but if an upstairs room or loft area everybody at the summer bbq will be asking why you look so pissed off. With 3 lights that may still happen, you may spend a considerable time on real low settings during those weeks/months even if on over night.
