morning
Are you thinking of snipping the ends of, getting new connectors, sleeving then re-crimping the connectors back on?
Good luck with that, the results can be pretty epic!!
Not 100% sure if OCUK do the connectors you need, so i would suggest dropping them a line to ask, failing that - Google knows everything, search for exactly what you need.
EG - in google i put - 24 pin ATX pins, loads of results come up