I have an 87 sami with a 3" spring under lift and im going to school and have a family so money is super tight. I would like to get a spring over lift but need to buy the components little by little so my question is what are all the parts I will need to make this possible? and if you know of a good cheap place to get the parts then please share.

I recommend picking up the basic SPOA kit form Sky Manufacturing.  It comes with the cross over steering and, extended brake lines and the wrap-around style spring pads.  Everything you need to put together your SPOA lift safely.  For the shocks you can just flip your spring pads  between the left and right side and use your current shocks, great for getting that rig on the road.

I have done it in my back-yard for free.  There is also a great build by khan_sultan over at http://zukiworld.com/forum/general-suzuki-forum/basic-spoa-on-a-lwb-sj-413-using-stock-parts that covers using all stock parts.

If your going to do heavy wheeling with a SPOA I would also look into a traction bar.  http://www.zukiworld.com/forum/general-suzuki-forum/traction-bar-for-spoa-edit-!!!!-now-fabricated-installed/

If you want to know what the basics that you need to buy (like piece by piece) here is a list this is from RRO bolt on kit so if you go to their site you can see all of this there too. Here goes

Front wraparound spring pads (I bought the weld-on pads from RRO I like them better then others I have used because they reach all the way down to the stock pads and can be welded there instead of on the axle tube which I learned the hard way is very weak LOL)

Rear wraparound spring pads (same thing here with the RRO ones)

2- 7" longer front brake lines

1- 7" Rear brake line extension (86-88.5' model years need 2 of these)

Front and rear drive-shaft extensions (I bought these but do plan to buy the heavy duty (HD) new drive lines still, just no money for them yet a friend of mine got the HD ones and he loved them he would launch it off the line and not worry and also land it right on rocks without worrying about busting the U-joints plus the HD ones are longer for the lift so you do not need these extensions)

Front and rear long travel shock mounting (I bought these but have not ever used the front ones, I do recommend the rear one as it tips your shocks inward at the top with out them I was punching the underside of the body)

Front and rear HD Ubolt plates (I think I used my stock ones but flipped them like Drone637 has already said to do)   

Front and rear custom Ubolts. (yours will most likely not be reusable after you get them off)

Custom height Zlink steering linkage (this is a RRO part I bought a 3" drop pitman arm if I do it again though I will most likely go with this or cross over steering as they are less likely to bump the steering when you hit a bump in the road or trail       

I did get new shocks too but that was in large part due to the fact that mine were way old before I started it all

http://www.rocky-road.com/boltonspoa.html