Scrap the mars.I just got one,the mars rep sent me a 900 as a tester to review and write good things about and it sucks.Im about to send it to back or give it to noob.I put it over some ghost train haze and they arent anywhere near what my CMH was doing.
I strongly suggest you run autos as your first grow.Your gonna have light leaks to deal with on a 12 12 schedule.Photo plants will have to have complete dark for 12 hours a day.Your already gonna have a plathora of bullshit to deal with as a first grow not having to struggle with light is another less issue.Also autos run fast.You can run a couple autos in 2 DWC buckets with the light at 18/6 and not have to do nothing else but add nutes and
hydroguard.in 30 days add 2 more and you can keep them all in the same tent under different stages so you can have a nice crop every 30 days.Autos will finish from sprout to chop in 65 days.Once you get the hang of growing than you can move on to timing photo strains.
Mephisto makes some solid auto strains that will ring your bell.People shit talk autos but ive grown them and gave it to the most seasoned smokers that didnt care wtf it was cause it was good.
As far as lights go a do it your self cob build can be great.They also make kits.Rapid Led has DIY kits they sell for 4x4 or 3x3 or whatever footprint you wanna cover.Higher up front cost but worth it in the long run.
Stay away from Blurple Leds and premade box light LED.they suck and the footprints suck.Go with a cob Kit or quantum board setup.
Heat wont be an issue either way with autos cause you wont need a tent at all.Just put the lights in a corner of a room and run em.You wont have to worry about light schedules and exhausting a tent when its closed.So on a budget you can go with a couple 315 CMH.you can get the ballast,bulbs and wing reflectors cheap.put 2 or 3 autos under each light and let em eat.The End,