Costume for Players
Boots and shoes avoid trainers,
Bottoms: Jeans, (try to avoid blue denim trousers) trousers, dungarees, bib and brace overalls, skirts
Tops: Shirts, tunics, plain single 'tee shirts, blouses, grandad shirts, vests,  avoid patterns, definitely no logos.
Layers: Waistcoats, braces
Outer: Coats, cloaks, capes, jackets. No military jackets unless mutilated beyond recognition.
Decorations: belts, straps, webbing, scarves, hats, sunglasses, goggles, kneepads, elbow pads, no logos, avoid patterns
  logos, army camouflage pattern, generally avoid military looks.

See link below for examples of style of costume you should aim for.

Equipment Phys-reps
Guns - most nerf guns fit the part, as do water pistols without obvious tanks or cylinders, they should painted to get rid of garish colours they come in. You can also find many reproduction guns however these can be rather expensive when a £ 5 water pistol from a car boot can look just as good.
Hand Weapons - Ideally weapons should look improvised, a wooden club, a large spanner, iron bar, spade etc.  You can find these on most lrp merchant sites selling latex weapons.
Other equipment - Almost anything goes here, you can have the improvised look or Star Trek tri-corder look, the colony brought along with it the full spectrum of equipment since older technology was thought to be more robust and repairable.
Avoid items that look alien rather than furturistic, if unsure ask us.

See links below for examples of equipment you should aim for.