What about a fresh modern PSU design for tube mics ?

While building tube mics is fun, I find building outdated PSU designs frustrating. I'm no electronic specialist, rather a classic hobbyist, nevertheless with data sheets of modern parts I might be possible for me. I would leave the high voltage designs it is in the old PSU and do a modern regulation for the heater. Voltage should be adjustable between 4.7 and  6.5 Volt. 800mA to have enough juice for two tubes. this part looks interesting, but I'd welcome any hints http://www.ti.com/lsds/ti/power-management/single-channel-ldo-products.page#p182=Adjustable%20Output&p451max=0.005;0.8&p634max=6.13;125&p634min=-47;6.4&p1128=3.8;28

another alternative would be to ask funk to build a batch of PSU. His PSU design is the best in audio  http://www.funk-tonstudiotechnik.de/PWS-04B-T.pdf