the hps lights or mh for that matter that you are looking at are not what you want to get. Checkout a good online hydro site and you will see what you need. If you need to know the places in TX where you can pick them up for cash I can help with that too.. there are a few indoor garden centers in the major cities.. you will need one sooner or later. Ebay is another possibility too.. you will want horizontal bulb fixtures for agricultural purposes with hortilux or another growing enhanced spectrum bulb. Money would be a waste on anything but.. and cooling them if you have a decent air supply is alot easier than people lead on.. but no they are not easy to cool in the back of a closet with next to no airflow.. just imagine cooling an incandecent bulb (or bulbs) of equal wattage and if you can handle that you will be fine.. a little bit of airflow over the bulb and some air exchange with the outside.. you should be fine