Name: Hot Air Balloon
Type: Aerial
Cost: 900
Support: 6
Attack: 15
Range: 0
Defense: 15
Armor: 1
Damage: 1
Vision: 3
Movement: 5
Fuel: 15
Abilities: Aerial - used for 19th century reconnaisance

Name: Provincial Governor
Type: Governor
Cost: 500
Support: 4
Attack: 0
Range: 0
Defense: 10
Armor: 1
Damage: 1
Vision: 2
Movement: 2
Fuel: --
Abilities: 25% reduction in production costs for all Defense units and Attack units in cities where Provincial Governors are sentried, BUT decreases those citie's happiness by 2 and by 4 after 20 turns a PG is present in those cities

Name: Modern Surveyor
Type: Surveyor
Cost: 820
Support: 6
Attack: 0
Range: 0
Defense: 10
Armor: 1
Damage: 1
Vision: 2
Movement: 2
Fuel: --
Abilities: establishes permnament national border from position where sentried for five consecutive turns of no disturbance

Your Modern Surveyor is totally impossible, at least with SLIC (and I don't think text-files can do it either). There's no way you can manipulate borders in SLIC, other then by building/destroying fortresses or cities.

The Provincial Governor is possible but requires a fair amount of work. What is needed is that you need to have all units that you want to be cheaper with a governer twice: these 'doubles' should be exactly identical except for the text-files name (though the in-game name should remain the same - so you need UNIT_WARRIOR and UNIT_WARRIOR2, but both should be called Warrior gl_str.txt)) and the production cost.

Then you need to use the SLIC function mod_CanCitBuildUnit and list all these units like this:

code:

---

int_f mod_CanCityBuildUnit(city_t theCity, int_t theUnit) {
city_t	tmpCity;
unit_t	tmpUnit;
int_t	i;
int_t	thisUnit;
	thisUnit = theUnit;
	tmpCity = theCity;
	cheapunits = 0;
	for (i = 0; i < GetUnitsAtLocation(tmpCity.location); i = i + 1) {
		GetUnitFromCell(tmpCity.location, i, tmpUnit);
			if (tmpUnit.type == UnitDB(UNIT_PROVINCIAL_GOVERNOR)) {
				cheapunits = 1;
			}
		}
	}
	if (cheapunits == 0) {		// if a governor is present then...
		if (thisUnit == UnitDB(UNIT_WARRIOR)) {
			return 1;	// ...you can build this
		}
		if (thisUnit == UnitDB(UNIT_WARRIOR2) {
			return 0;	// ...you can't build this
		}
		if (thisUnit == UnitDB(UNIT_ARCHER)) {
			return 1;	// ...you can build this
		}
		if (thisUnit == UnitDB(UNIT_ARCHER2) {
			return 0;	// ...you can't build this
		}
		// etc. for all units that have two versions
	} elseif (cheapunits == 1) {		// if no governor is present then...
		if (thisUnit == UnitDB(UNIT_WARRIOR)) {
			return 0;	// ...you can't build this
		}
		if (thisUnit == UnitDB(UNIT_WARRIOR2) {
			return 1;	// ...you can build this
		}
		if (thisUnit == UnitDB(UNIT_ARCHER)) {
			return 0;	// ...you can't build this
		}
		if (thisUnit == UnitDB(UNIT_ARCHER2) {
			return 1;	// ...you can build this
		}
		// etc. for all units that have two versions
	}
	return 1;	// units with only one version can always be built
}

---

And finally you'd also need to write a happiness-trigger which is slightly more complicated and I don't have time to write that now.