Ive got the stage two HHs setup from Simons CPR!! Sled runs awsome!!
Sorry you havent had many replys ,,, Just sometimes seems like these questions has been asked a million times!!
I would run 144 studs as you stated if you have a 1 1/4 track if you have the Stock POS track i would run as close to 200 as possible.. Running as many as possible in the middle!!(opinions vary on this)
Easy to find this information on track studding according to what brand you run (just go to the brands website and they will tell you how many and what length for your sled)
personally i dont worry about the brand as much as the quality... Stainless steel with carbide tips... Ran cheep ones in the past and had NO failers after 3000 miles!! GET WHAT EVER IS THE CHEAPEST.. I have used round plastic backers in the past with good results and now have aluminum square backes and have no problems as of yet eather!!
Run studs 1/4in to 3/8 in longer than the track you have!!
Hope i helped , you can email me if you want any further help...