Are you going to be on the road or all out crawling? how tall are you going? this matters cause of the amount of anti squat. the best for the rocks is no good on the road and the best for road is no good for super high articulation. triangulated 4 link with coil overs or three link with a tack bar is awesome for high articulation but a y link style four link is cheaper and will get you alto of flex the shock angle just doesn't matters long as they are as close to straight up and down as you can get them. the more you lay them down the longer shock you can use but the more you give up on the shock doing a proper job. The longer the shock the more drop you get providing everything else is set up correct so there won't be binding. Also check the valuing in the shock find one that suits your style of driving. For example i drive very slow and technical i crawl so i have a set of cheap 31" extended 17" collapsed shocks (sorry i don't remember what the valuing is on mine) to give me drop and move more freely. if i was racing king of the hammers i would want something with a valve set up to damper the weight for going out of control they would be stiffer
I'm in the early stages of a design on my FJ40...rear will be a double triangulated 4-link with 14" stroke shocks. Front will be a 3-link w/ panhard running hydro assist steering.
My old (and heavy) rear suspension consisted of a 'splayed' 4-link running 1/4 ellip springs and 14" shocks...it handled great on the road and the trails. Find the 'four link calculator' online and use that to test out your numbers...my antisquat values were in the 85-89 range with 39" eye-to-eye upper and lower links and 39" tires.