I have a 400w HiLux HPS. Worm's Way(company) actually sold that one to me over the Hortilux which is almost $20 MORE. The HiLux puts out more lumens also. They said that all of the 400w customers who had tried the HiLux said they prefer it over the Hortilux, and not just because of the money saving. Supposedly they last a bit longer also. As for the cool tube, chech Pyrex bake-a-round tube on ebay. I picked up two of them for around $30 with shipping. If not, there are some links for some sort of glass candle holders somewhere around here...
Good luck, stay safe, PEACE.