I haven't notice any other make with the proper diameter. It is a slip fit and should be fairly easy to remove. If it's been in a while, you may find it easier to drop the pan and drive it out from below. A car dipstick can work on a truck. It has to be shortened. Once installed, the oil will only cover about 1/4" to 1/2" of the tip. Do an oil change at the same time and you can mark the level when full. I've been running like this for years. The plug in the timing cover can be used to plug the hole in the block when the dipsticks are swapped.
To my knowledge, Lokar does not make anything that will fit. I tried to order a custom dipstick from them several years ago. Their custom department was not impressive. I gave them 2 tries at making the fitting for the block with the required dimensions. They failed both times. I, with maybe 10 hours total of machining experience, used the lathe at work and made the part exactly as needed. Now, it's been several years and that "machinist" may not be there anymore.
Lawrenceville, GA