Having recently purchased a compressor and abrasive blasting equipment, I have a number of opinions on the topic. I was going to write a long-winded article on the subject Real Soon Now, but your inquiry prompts a somewhat earlier set of comments.
Unless one has a very large number of parts to be blasted, and the time to do the work himself, it is almost always less expensive to hire abrasive blasting done than to acquire the capability at home. However, as you noted, one may not be able to find a competent craftsman willing and able to do the work.
Abrasive blasting uses a tremendous amount of compressed air, and adequate air compressors are by no means inexpensive. New equipment is generally the most reliable approach, but requires a major initial investment. The most economical way is, most likely, to buy a used compressor and whatever it takes to rebuild it. This, of course, has certain risks, chief among which is an air tank that's about to rupture due to internal rust. I imagine that one could have a used tank inspected and re-certified, but this would likely cost as much as a new tank alone.
For the compressor to be useful for abrasive blasting, it will have to provide AT LEAST 6 or 7 scfm of air at 90 psi -- or twice that, for professional uses. If the compressor is to have a decent lifespan, it must provide that much air when operating at a duty cycle of not more than 75% and preferably less. Here in the US the least expensive compressors of that sort sell for US $350 or so. You'd also need a decent hose (3/8" inside diameter) about ten percent longer than you think is necessary, and a handful of fittings and couplings of various types. Buy only quality hose (though not necessarily name brand ones). The cheap plastic ones are far too stiff and do not flow enough air. In a moist climate, a filter to remove water from the air is also necessary.
There are basically two types of abrasive blasting gun. The siphon type uses airflow to suck the abrasive up from the floor of the blasting cabinet, or from a remote abrasive container of some sort (e.g. a bucket). The reservoir type stores the abrasive in a container attached to the gun. The former is easier to use, the latter is slightly more versatile. Costs for the guns are relatively low, so there's no reason not to buy one of each type. You will want ceramic or exotic nozzles -- these wear out quickly, and it is useful to have spares immediately to hand. You'll also want to stock a quantity of each of o-rings or gaskets used in the blasting gun -- these can fail without warning. O-rings are available in bulk from industrial suppliers for a couple of US dollars per 100. I do not recommend o-rings made in Mainland China as they are very soft and seem to wear out almost instantly.
Although abrasive blasting cabinets can be used indoors, only the large professional types seem well-built enough to not leak. Dust is a major issue, and so for hobbyist grade equipment, I would consider an outdoor setting essential. Weather may thus restrict equipment use.
No matter how big a blasting cabinet you acquire, you may eventually find yourself wishing for a larger one. I suggest starting with the biggest blasting cabinet affordable, or, if you're handy with woodworking, building your own. If using a siphon type gun, you'll want a cabinet with a steeply sloped bottom so that the abrasive will flow back to the siphon through gravity alone. Alternately, you could do away with the cabinet entirely, and do all your blasting inside a thick-walled plastic bag.
You'll want two types of abrasive: glass beads and aluminum oxide. The former is best for finishing soft metals, and lasts a long time. The latter cuts through rust and paint better than glass beads, but tends to be dusty and more seems to get lost in use. You'll want to start with about 25 pounds of each type. Keep the stuff absolutely bone dry or you will have problems getting it to feed through a siphon.
You will absolutely need respiratory protection. A cheap paper dust mask is not enough to keep your lungs safe -- you'll need a good respirator and lots of replacement filters for it. You can greatly extend the life of the respirator's filter by placing the cheap paper dust mask over its air inlet.
You will also want eye protection of some sort. For me, safety glasses work well with a sealed blast cabinet. For any more open blasting, I'd definitely want sealed goggles of some sort.
Finally, others may disagree, but in my opinion one should NOT EVER use an abrasive containing free silica (e.g. sand) unless you use a full-head mask with a purified air supply of some sort. Silicosis is a miserable way to die.
Finally, once you have all those nicely rust-free parts, you'll want to protect them from further oxidation. This usually means paint. For small automotive parts, I recommend an inexpensive air brush. Adapters are readily available to connect an air brush hose to a standard air fittings. Paint usage is incredibly low -- a pint can last for years.
Mark Rosenbaum Kingman AZ 74 JH 16371