Hortilux now has a Blue 600w MH. Pretty sure that has to be an HPS conversion so that would work for you if you wanted to switch to mh for veg.
Def get yourself a digital high/low thermometer and hygrometer. Look on Amazon or at the garden center.
It varies by strain but some general numbers are as follows. Ideal temp ~ 72, no more than 80 in the day, no less than 65 at night. ASSUMING you have proper air flow and nothing that attracts mold in your grow space... RH for seedlings/clones should be around 70-80%. For Veg around 60-70% and for flower 40-60%. Digital high/low meter is a must unless you wanna wake up every night and check your temps and rh.
Also don't bother with litmus ph kits (the color ones). Practically impossible to PH nute solution with thos. Spend ~$50 or so on a digital spear type ph meter, Hanna is the most popular, although I use a more trusted brand. Also make sure you understand how to calibrate it and do so once a week. I do mine on fresh water day, as I give them fresh water near then end of every week to help prevent build up.
Don't worry so much about the ph of your grow medium itself. Just make sure when you feed/water, the solution is at a good ph and slowing fill the pots till you get 10-20% run off. Then once a week give them fresh ph'd water in the same manor, the nutes will be mostly avail regardless of the soil ph itself.