Ok first this is on an 81 blazer frame and drivetrain, but we are putting a single cab nissan hardbody body on it. He wants to get a decent amount of flex out of it but is also on a budget. Would it be more effective(thinking travel and $$$) to run revolver shackles front and rear or do a 3-link front and 4-link rear with coil springs.

Oh and he is not planning on running shocks since it wil only be a trail truck, is this ok or very bad?

I think you should run the revolvers all around, no shocks, then paint

DANGER

all over the thing so people know to stay clear for their own safety.

Ok call me stupid but after you do explain why you say that. I have seen people run revolvers front and rear and heard its fine. Also been told that it is ok to go without shocks for strictily offroad and extremely slow speeds. I definetly dont know a whole lot about this but im trying to learn so If you could atleast explain your reasoning behind it.

if you don't know a lot about it then you should rule out a linked suspension now.

and be serious- it will not ALWAYS be super slow. i would never want to do any sort of hill climb without shocks.

if you're looking cheap, then go a soft leaf spring and then ProComp and BDS make some decent shocks for cheap. I was using the ProComp 3000s (cheap and easy to find) and they worked fine with mine being a DD. I just took them off (after 2+ years of DD'ing and wheelin) and replaced them with the BDS 14" travel. they seem to do a little better on the road (not that it matters in your case) and they were slightly more than the ProComps.

either way it should be in the budget for ya.

if you want it to flex put 88-98 chevy truck rear springs on the back of it with a off-road design 2 1/2" reverse shackle hanger with a 6" shackle and put the stock blazer rear springs in the front. I did this and it flex's pretty well and is totally safe.

Instead of buying ORD's shackle hanger you can get another set of front hangers (rear spring) and do the same thing cheaper. RUN SHOCKS! If it's a cost thing look for part numbers ending in 150 and 160 from scratch and dent.
The stock rears work good on the front, but be prepared to do something with your steering.

run old style ford front suspention its really easy and super cheap. then use jeep tj lift coils on the front. out back run 63" chevy springs with two leaves. you'll get plenty of flex and run shocks no matter what you do. ive been driving my ranger around with no shocks for about a year now and i hope someday i quit being lazy and make some mounts its crappy without em.