An idea would be to use a Weber Charcoal Smoker and Apple/Oak/Cherry Wood Chips (of course you can use different types of chips
, but some of them may not work well with malt/beer).
When it comes time to kiln your malted grain, simply take the amount you want to smoke and place it in a small strainer or colander (think flour sifter with the handle cut off) suspend that in a small bowl or dish to allow the smoke to get around it. Place it on the upper shelf in the smoker. (Assuming you have your charcoal going and the wood chips in the water dish.)
With a little practice you can regulate the temperature to kilning temperature and just kiln in the smoker for as long you normally would. Ensure that you stir your malt once or twice an hour just as you normally would. (Discard the rootlets that fall off before putting the malt back in the smoker.)
It would take more attention than normal to regulate the temp, but it is doable.
Might have to try a couple batches to determine the amount of custom smoked malt you need and to get the hang of kilning it in the smoker.
Unlike proper barley for brewing, it seems that the proper wheat is easily available and so I'm thinking this would be a good candidate for trying to malt and smoke some myself.
Not sure what you mean by "proper" but barley, wheat and corn for malting purposes should be readily available across the country.
Malting is fairly easy if you pay attention to details. Plus it'll make the beer more your own by giving it the flavors you control through the malting variables.