Can I replace my OEM boost gauge but keep its look/location? Yes. Due to the unusual mPa reading of the Lamco gauge, it is a quite popular swapout. In order to do so, many will replace it with a slightly larger unit and use the same housing. Grease for lubricant and a hair dryer to soften the housing are all that are required to install an aftermarket unit as they are usually just 3mm larger than the stock gauge. It take some work to get the new unit in there correctly, but it can be done.
AFAIK the only gauges that can be installed in this manner are the Omori 45mm ones. The OEM Lamco is 42mm. I haven't seen any other aftermarket 45mm gauges.
Omori has both electrical and mechanical versions, with different needle coloring and illumination for matching the various years/models. The most versatile is the "full color" type which uses multi-color (red, green and blue) LEDs for illumination and is adjustable for any backlighting color desired.