look up on you tube or google

airhog-custom cnc work amazing (best know for his one off a5's)
englers- custom real fire arm work (the king of custom)
warcowboy- custom airsoft to paintball work (p90/g36)
noxx55-real gun/cnc/airsoft to paintball work (automag pump star more old school)
oily-real/cnc/airsoft to paintball (his qloaded saw is teh king of saw's)

and get a custom made milsim gun made by them(they all do there own custom guns in real gun/airsoft/custom cnc work)

these above guys are super stars of the custom woodsball gun market

for pre bought market not on the norm

thunder mad max gun (double barrel launcher)
rap4 canister launcher (6 shot of any 40 mm canisters)
B5 - a5 in diff body mor bullpup
ata tsg1 (mag fed psg 1 sniper clone)
wasaga beach monster (4 flatelined a5 on joy stick control fed by a 6000 round back pack)
the umber mini gun 6000 rounds of airsoft paintball pellets in a min

or the super star the paint thrower real world war flame thrower converted to shot a stream of water soluble paint 300 yards away ( getting hit by this will end your day of paintball, cuz u will be covered head to toe

and for the lazy paintballer just get a warhog from specops and drive and shotlike a champ

added some just for the funny aspect, in a scenario game or in any game in the woods marker dont matter anything will work. buy what feels right