First off you need to provide a little info about your truck. Might I suggest adding some specs to your signature area, by doing that it'll be available every time you post a question rather than having to repeat it. Item number 1 would depend on your truck, but generally speaking I'll have to say no. Technically yes they will work if you've got coil springs, but your ride will be poor as hell. Using those compressors lessens the the springs to do their job of compressing and rebounding, which will make for a very rough ride. The second item won't work on a stock Ford Ranger unless you want to lift, even then you'd probably be SOL since the dimensions are likely wrong.
How much do you want to lower your truck? What kind of stance do you want it to have, rake (back notably higher than front) or level?
I'm going to assume you have a 2wd. The front suspension options mostly depend on the year model, pre 98 or post 97. Pre 98 you can use drop springs to get up to* 2", drop I beams to get up to 3", or combine them for up to* 5". (* assuming you don't cut them) For the post 97 you can use control arms and/or springs, but I can't tell you how much drop to expect. On the rear things are pretty much universal between the years you can flip the shackle/hangar for about 2", flip the axle(put it on top of the springs) for 4" or 5" depending on the axle, or lowered leaf springs. Blocks and shackles can be used in conjunction with the flip kit for a little more or less drop respectively. Like on the front different methods can be combined, but after a point notching the frame will be required.