HID: Several small lights or 1 big light?

Say for example I want a 600watt HPS grow, is it better to get 1 600watt light or 4 150watt lights to evenly spread the light?

Cab would be around 10 sq ft (4'x2.5')
Will be growing at least 20 from clones on hydro.

Well, just from a cost factor I'd go with 1 - 600 hps.

(using pricing on Amazon) you can get 1 - 600 hps for around $180 and each 150 hps is around $80.

Also, dealing with all the wiring and cords would be a hassle. I'd probably just jump to 2 - 400 hps, more overall light, less money and hassle than 4 - 150's, and great coverage for your 10 sq/ft.

For the size just go with the 1 600W. Coverage will be good for as small as the growing area is.

Yeah, just get a 600. A 600 will do 4x4, so 4x2.5 is a little wasteful, but it's still your best option.

Thanks for the replies! Yeah with the size of the cab, 600 might be a bit over, 400 might be a bit low. I think a better light would be 500 but I haven't seen that size in the store where I'm buying. There are 250 though- I can get 2.

Before I decide, my biggest concern is getting multiple lights vs single light. My cab is wide but thin- and I'm worried that the plants that will be placed at the ends might not get the same amount of light.

Just wondering if having multiple lights will have better distribution. But maybe my cab is too small for me to worry about that.

Here's an option. Get a 400W HID (MH for veg, HPS for flower) and then add in like 100W of CFL. I've got a 2x5 closet (10sq feet) and this will give me a nice 50w per square foot with super HPS light and supplemental 6500K CFL for added blue spectrum and a larger footprint.