The only option in 1999 was the exterior color. The black and grey seats became an option for 2000-2001. These are the only "options" that I know of.
The factory alarm system is the same in all VXes from 1999-2001 (and probably the same in a number of other Isuzu SUV's). You can buy a replacement here: http://www.cruisingforremotes.com/on...7131&storeid=1 as well as numerous other internet retailers. Do a google search on "OEM replacement remote auto alarm" and you'll find a ton of them.
The OME lift isn't a kit, it's a brand name for springs called "Old Man Emu". Specifically, the OME 912 springs, originally designed for the Trooper, can be installed in the rear of the VX to give you about 2-1/2" of lift. It is also recommended that you replace the rear shocks with the longer trooper shocks. The front can be lifted by cranking the torsion bars. OME springs are better than Calmini, and you can choose whatever shocks you prefer. Many owners here have gone with the Rancho 9000x series.
Do a search here on "OME lift" to find tons of information, caviots, and other mods that can or should be done with your lift.
Calmini Cone Air Filter, PowerVault PV2 Muffler, OME Trooper Springs, Rancho RS9000X Shocks, 285/75R16 Nitto Grappler AT's, Pioneer DEH P8000R In-Dash CD, Amps and Drivers Built by Orion, Wires and Fuse Blocks by KnuKonceptz, Vibration Damping by BQuiet, Alarm System featuring Auto Start and Remote Windows, Yakima LoadWarrior w/Full Size Spare, Debadged/Custom Titanium Grill Logo, Tint (5% Rear / 20% Front), Steel Braided Brake Lines, G2 Painted Calipers