I use 2700k and 6500k in my flowering room. 1 6500k per 2700k. I like to get the full spectrum.
IMO, plants grow alot faster in the veg state with 6500k than 2700k, but they will also grow with 2700k bulbs.
Buying a 4 pack of 23 watts bulbs is prob cheaper than buying 1 65watt bulb. Only thing is, you'll have 4 lights hanging around instead of one. So the choice is yours.
Edit: Well never mind. I thought about it and it may be cheaper to run 1 65 watt bulb. Because running 4 23 watt bulbs you'd have to get 2 plug-socket adapters and 2 Y adapters costing you more than runnin 1 65 watt bulb.