Try and do the titration with KOH if you're going to ultimately use KOH, then use the titration results just like you would have with NaOH. The titration you do with the two different chemicals (ie 1/1000 NaOH versus 1/1000 KOH) is going to be give just slightly different results. Otherwise, if you're going to use NaOH for the titration and KOH for the actual reaction, multiply the NaOH's titration results by 1.4 to compensate for the fact that NaOH is that much stronger than KOH.