WTF! I replied to this yesterday, where did my reply go? **Don't I look stupid, my earlier reply is back now.**
They make 2" drop springs, but you'll probably only see about an inch of actual drop due to engine weight and spring sag. The also make 3" drop springs, but from what I've heard they are damn near non-alignable wit the stock beams. You can cut your coils but need to be careful about it, too much and you make the spring useless. Cutting 1" of height off a coil does not equal 1" of drop, and you can always cut more off but you can't add it back on. Most proponents of coil cutting will recommend cutting a quarter of a turn at a time, then test and repeat as necessary. It is a longer process, but you can get the height you want with less risk of ruining the spring.
For the rear, if you are still running a stock axle a flip kit is the easiest way to get 4" drop. If you are running a larger 31 spline 8.8" or a 9" an axle flip will probably give closer to 5" drop.
You will need other things in addition to springs and flip kit. Stock shocks are usually good up to about a 3" drop. 2" Drop springs or cut coils will still be okay with stock shocks. With 3" drop springs you might want to consider drop shocks the drop may cause stock length to wear out fast. With any drop spring you will also, need to add adjustable camber eccentrics, so that the alignment can be brought back into spec. It's much better to add them yourself than pay the shop, 3.5º eccentrics can be bought from NAPA. IIRC they go into the upper ball joint lug on the spindle. For the rear you definitely need drop shocks with that 4" drop. The stock length will be constantly bottoming out, which kills the shock, and they will ride like crap.
Its more drop than you are looking for, but I recommend going with drop beams up front for a 3" drop. IMO it's a better option than drop springs in every way, except for price. Drop beams do not require drop shocks or camber eccentrics unless used in conjunction with drop springs.