There are controllers out there to replace air over hydraulic with electric over hydraulic, but the question as always becomes, what are you intending to do with this trailer? It's heavy, short length, high center of gravity, lots of tongue weight, and way overspecced to be towed by anything that isn't large enough to need air brakes. For the price of modifying the trailer, and the value of the trailer afterwards (which is almost always the same as what it was before you do any conversions like this) you're almost always ahead in the game with either purchasing or building a trailer that meets your needs.
The answer to this problem 98% of the time is either buy a bigger truck to tow it with (that has air brakes) or sell the trailer and buy/build something smaller that's better suited to be towed behind a pickup.
However that 2% of the time where the solution isn't doing something else, if you can explain to us exactly WHY you need to have this trailer to tow behind your pickup (which you haven't mentioned exactly what type of pickup it is, but if it's smaller than a 3/4 or 1 ton truck the only responses you will receive are that what you are thinking is extremely unsafe/stupid, and we don't want to be involved. That and the fact that unless it's a pickup that's been lifted at least a foot the hitch won't come anywhere near being the correct height, (which we'd still probably not want to have any part of as a high center of gravity truck towing a high center of gravity trailer is just asking for trouble) you'll have to spend even more money either lowering the trailer or adapting the hitch somehow.
Easiest solution if you really want to use this trailer, install a different axle with electric brakes, possibly different axle springs to lower it, and smaller wheels/tires to lower it further. At that point you'll have a trailer that easily connects (or more easily) behind a pickup, but the chassis will still be pretty heavy compared to most civilian trailers.
