Most people these days will have their chassis powder coated, it seems expensive but bare in mind that if applied correctly on a sand blasted surface it will last a long time and add to the resale value of your car.

The alternative is hand painting which requires much preparation and is unlikely to yield a first class finish at a reasonable cost. Whatever method used it will only maintain its protective qualities if cleaned and polished at regular intervals. Where it cannot be maintained other forms of protection could be added.

After powder coating the suspension components and engine bearers they need to have the rubber bushes inserted. Try to find someone with a hydraulic press for this job as even a good vice will struggle and could break if you are really unlucky. Before pushing the bushes into place file a slight chamfer around the opening to ease the bush in, the powder residue inside will help as it acts as a lubricant. If pushing the bushes in to an untreated component some grease will need to be applied.