That's a nice new big space! I'm sure he will enjoy it. The T8 is a bit low power for such a large enclosure. You will need to create a branch or space large enough for him to bask that comes within 6-8'' of it and provide basking temps for it to be effective. Ultimately you'll be better served by a T5 with a reflector that can sit 12-14'' above the main basking area and still provide daylight levels of UVB. They are absolutely worth the investment.
They are both quite good and pretty similar in output. My Arcadia has lasted 3 years so far without needing a bulb change (output measured regularly with a Solarmeter) so I can say they have great longevity. Your mileage may vary though.
I'd stick with the 10.0 or 12%. The 14% is a newer bulb and quite strong. Best suited for very tall tanks. The 12% will provide adequate UVB levels at 14'' but if you can build a branch or something to allow access closer to the bulb if desired that may be a good idea.