Island Deathmatch

[another_nonsense]

Hi, me and some friends are looking to do some PvP sessions using GURPS, while we have had great success in the past with a reasonably size "ghost town" style arena it makes allot of character customisation moot and heavily supports certain builds.

My idea...

Spoiler:  

My idea is to scale up to a small island (Something like the island in battle royale here but perhaps something more tropical/varied; adding an overland map split into different zones and terrain types. travel will take time and involve rolling on random tables for each zone/terrain type allowing for certain events and such.
This in itself opens up a whole new options when designing characters making skills like survival, tracking and such instantly important. As travel takes time characters will have to seek shelter and feed themselves over extended periods. If extended survival is required early encounter might even end in temporary truces (...maybe? wishful thinking?). Either way this opens options.

Encounters would be dealt with by entering smaller maps with a hex grid (or squared depending on system), two or three for each terrain type at least.

What I am looking for specifically is advice on software etc to make/gather these maps. I'm also open to people's ideas as to events and such. the end result should be reasonably system neutral so anyone can use it with their system of choice.

Initially it will be a deathmatch scenario but I'd also like to develop other modes such as capture the flag or king of the hill or a point based scoring system.