The bulbs with 6500K are usually made with green ends. You can buy them individually or by the case. The Kelvin rating is listed on the tags, signs, and packaging.
I think Home Depot has the oddball lengths as well, but the nice thing about VHO endcaps is you can move them. A 48" bulb is more like 47", and with endcaps, it should fit in right at 48". So if you have URI shorter bulbs, you can move the other endcaps out slightly to accomodate the NO bulbs. (NO means Normal Output)
Skimmers - The Euroreef is more expensive, and the ASM is a cheaper knock-off of the ER. I'm not putting the ASM down. The owners of ER parted company, and the guys that left started up ASM and had to make their own version with slightly different parts to avoid a lawsuit.
I personally recommend in-sump skimmers, but there are HOB ER skimmers. Maybe ASM makes them as well, but I've never looked into it.