For the sake of accuracy, LDMOS (Laterally Diffused Metal-Oxide Semiconductor) is a type of high-power FET (Field Effect Transistor); examples include the BLF188XRS (1400W output). There are also VDMOS FET devices (Vertically Diffused) like the VRF2933 (600W output per pair). These are generally optimized for high-power and high linearity (broadcast ?) hence they need high supply voltage, not very suitable for portable equipment. They are generally +50V devices, even if +28V parts are not uncommon. Haven’t seen an LDMOS/VDMOS designed for +13.8V operation yet (even if I’m sure they exist).
What we need for portable operations are devices optimized for linearity at 12 … 13.8V so we keep optimal efficiency. The circuit in @KN4BEV 's link uses a pair of 30W 12.5V bipolar transistors, so the max you could expect is about 50W output. It is not an amplifier but just a amplifying circut, that will still need filters and control/protection just to be usable. The builder (4Z4RB) is quite known and experienced, even if the assembly quality looks poor (mostly because of the home-made PCBs).
The link provided by @DD5LP shows an amplifier that uses FET transistors not designed for RF but for switching, which means they are cheap but there are downsides: quickly degrading gain over ~15MHz, easily damaged, etc. You also just get the amplifying stage of an amplifier and will need filters, control, protection etc.
Something practical for SOTA would be this, which is a complete solution (amp, control, filter) that puts out 40+W at 12V and 100+W at 24V:
Or if you are looking just for the PA stage:
You can find them even cheaper on Aliexpress.
These use an undervolted +28V 120W part (MRF186). The case is lightweight, it’s very compact and because it the power RF part is designed for much higher power you can expect good ruggedness/reliability.