Lefty, depending on how your set up you will determine a lot. Take a look at what your going to blast. That will, to some extent help you decide "how and what" is actually best for you. Although I use fine sand for 90% or the stuff I blast, I also have some plastic, glass beads, and garnet for my cabinet. When I did blasting outside it seemed I used sand all the time.
Personally, I sold my pressurized blaster for half what I gave for it. Unless you plan to do a lot it may be better to get it done by someone else. For example my frame was really bad and I used a LOT of sand. For a few more dollars I could have had it blasted and not had the headache. To blast you also need DRY air. If not, you'll spend more time trying to unclog the system than blasting. If it won't go in my blasting cabinet it goes to a friend that does it.
...another thought is maybe someone who does mobile blasting. My neighbor had his 50 GMC blasted last summer. Cost him total of 300 bucks. Guy came to his house, brought the sand with him. (Same sand I use) and had a helper with him. He's been blasting for almost 20 years. The GMC was apart so it was all blasted. That was a deal. 3 hours and he was gone, truck ready for next item on his list.
Ultimately the decision is yours. Since we all are just giving our opinions I'd suggest, depending on your system, sand that is sized. No sifting, and it helps to keep system unclogged. I pay 4.35 for a 50lb bags (easier for me to handle) and its sized. Fine, X-fine, or medium from the local place I buy my concrete from.
Good luck, hope some of this helps you in your final decision. Let us know how you do.
