The best/cheapest spring compressor for the job is the one that fits down the center with one long bolt. I got mine at Advance Auto. It's still a tight fit, but it holds strong when compressed and you can use an impact wrench (lightly) with extension from up top. Otherwise, it will take forever turning the compressor(s) with a wrench, and most ratchets won't fit.
The strut compressors will need to be cut down to work correctly, as stated already, but I find them much more dangerous. I tried them the first time because I had some already, and they slid loose multiple times, mostly releasing the spring. The spring will also be extremely difficult to put back in place with these, so I would suggest not using them.
The more expensive single action compressor, such as the one at Harbor Freight Tools, works also, but can be kind of annoying. Probably the best option, although they are very cheaply made.
No matter what you do, be sure to lubricate the compressor threads with PB blaster or any similar oil. The job isn't too difficult, as long as your shocks, perches, and control arms aren't rust welded together... like mine were