So, I've attempted this in the past with very little luck, I'm wondering how i would be able to run several low wattage HPS lamps (Talking 35W, 50 or 70W) in series, without them being under/over driven or cycling.. is it possible with the current ballasts avalible on market? like for instance taking a 1000W ballast and putting the lamps in series, with some sort of capacitor or resistor or something in series with the lamps to make them operate properly (I'm not an engineer so I'm not sure how to go about this.. and i really dont want to do trial and error for this specific project if i dont have to as I dont really have the resources to waste)... any ideas? I dont plan to do this soon... as i dont have any 35W or 50W lamps and only 4 70W lamps nor do i have much of a selection of unused ballasts (most I've used in my homemade lights) other than like one 400W hps ballast and a 150W one... I'd imagine a strand of several HPS lamps needing more than that...

Well, any combination of loads in series will receive less than the total voltage of the circuit (it will be divided among all loads). To make such a system work, you would need a very high OCV from your ballast.

I reckon the 'ol fulham workhorse has some chooch in the voltage dept. Ive had it create a glow discharge in the outer bulb of a hot 100w MV when hot re-striking . Not sure about the safety of that though... well... its probably not safe. Thats a pretty cool idea if you can pull it off though!

You would need a ballast, where all the voltages intheir load curve are multiplied by the number of lamps in series. I dont think there is anything like that made comercially.
Except signage rubing and some electronic fluorescent and LED ballasts.

2 55V lamps + 2 matching ballasts for 120V, in series on 240V. For ignitor use a 400W+ European superimposed ignitor