Hi Fryinpan, welcome to the mad house, we are a friendly bunch, i promise!!
I am 6'3, and there aren't many boats I can stand up in, keep looking around though, you will come across one with headroom, either with deeper hull or taller cabin, but as long as it is in proportion and budget, then all is good, although you may struggle with 6K. Go for a wander round boatyards and brokerages, as you get to see a few at once, you will get a feel of different builders and styles in a more economical way. If you have any questions, don't be afraid to ask, there are plenty of people on here with a plethora of useful information, just waiting to pass on!
Another thought is if you are good with DIY and have mechanical experience, look on boatwrecks.com, they sometimes have boats pop up, usually fire damaged but sometimes a bargain can be found, as forum members on here have in the past.
Regards
Dan