Over the last few weeks I've been trying to develop the three characters, firstly thinking about the archetypes, so far I've been mainly focuings on Angel Eyes and Blondie.
For the setting I settled on a exotic planet with large jungle/rainforest like locales. For this I imgained spores that were hazardous to people ergo, outside interaction would need gas masks. Ideally I want the three characters to portray a different aspect of being a gun man. Blondie will be a classic bounty hunter whom will go where ever needed for the job such as outside in the exotic jungle/rainforest and would need cover such as the iconic poncho, a constant air sanitizler (gas mask) and special equipment to deal with nature. Blondie's style I imagine as being similar to Star Wars' aesthetic
Angel Eyes is a person I imagine if he as more modernised as a hit man of sorts. Always making sure his hands are clean from the kill but enjoys the job and the life that comes with it, giving him a slight edge to make audiences think "oooh he's a bad 'un". His style I imagine being slick and calm/cool with an aesthetic similar to bladerunner. More like a suit style.
Trying to combine these aesthetic I have in mind are going to be an interesting challenge but already I'm getting flashes of how it may be possible.