The recon units (infantry, wheeled, tracked AND helicopters) already included in-game AND historically supported as being used for said tasks in this era should be plenty efficient at spotting/infiltrating. There's a great variety of recon units in game, armed with a great variety of weapons, supporting a great variety of recon TACTICS. If you'd like an outline of said tactics, I'd be willing to humor you and would describe some.
Besides the historical facts of no real-time photo recon existing in the 70s and 80s, how many points would you be willing to spend for an SR-71, a U-2 or a similar strategic recon aircraft? They'd break the unit pricing system in the game, because they'd cost about 400,000 points to activate and use if weighed against the cost of other weapons systems included in the game.
Further, aircraft like SR-71s and U-2s were (and are) are tasked with missions that are planned at the HIGHEST levels of military command. You, as a mere lowly frontline commander of rusty tanks, sweaty men with rifles and throwaway combat aircraft would have no say whatsoever in the tasking of such assets. It's just absurd to claim otherwise, and exposes what you want as a "gimme!" sort of addition to the game, to add what you feel is a coolness factor, similarly to the whole debate over super hardcore snake eating two man sniper teams that will win a match for you.
Not trying to harsh your mellow here, but what y'all are asking for is way, way outside the scope, design, intent and mechanics of the game. EVEN if such mechanics were included (which would require a tremendous amount of work on restructuring the game to avoid them turning it into some sort of weird C&C mess), Eugen's already said repeatedly that they will NOT be adding more units into the game. They have a crazy amount of work to do polishing and balancing the game as it exists now, so give them an opportunity to improve everyone's gaming experience before you launch more campaigns for out-of-scope units to be added. Aren't hundreds upon hundreds of historically employed units enough?
Find me another RTS that has this many real-world units represented. Please, I'll wait. Oh, you can't? Well, there you go. ALB is arguably pushing forward the state of the art in modern military-themed RTS design, and it isn't enough for you.
Y'all remind me of someone who sits down at a massive, sumptuous banquet, complete with virtually anything you could ever want to eat, and says "BUT WAIT, why isn't there a peanut butter and jelly sandwich here??? It would complete my meal and I won't rest until I have it!"