Are you building this legit, or setting up the city by cheating items in with NEI? If you are cheating them in, GT or advanced solars, has a block that provides infinite EU for use in adventure maps. you can use that to power your city. If you are using the normal sandbox mechanics, you will need a fuel source of some kind. If you are planning to supply lots and lots of power to the city, a 33x33 plot isn't that large unless you went all the way down to bedrock.
For MJ, the most efficient method is the railcraft boilers. I would recommend using a liquid fuel source like biomass. There are numerous methods for making biomass and converting to biofuel. You could also use a few distilled/refined beed to make oily propolis to turn into buildcraft fuel. That would also be a good option. Bees to refinery to boiler could be made pretty compact. You could expand the number of alvearies depending on the size of the city. It should be completely renewable, and able to be completely automated.
Additional edit:
if you run steam from the boiler, run steam lines to all the plots and give everyone a commercial or industrial steam engine to tap into the MJ power. You can run lots and lots of engines off the steam lines.
Edit:
My current base that I'm building is going to be primarily powered by a 21x21 cane farm running off the old sugar cane farm from forestry. The cane is planted on the new Xycraft soil, so I have a 200% efficiency farm. Every single block is filled, and every tick update counts as two because of the xycraft soil blocks. The cane is converted into compressed plant balls and then into IC2 biofuel cells to burn in diesel generators. I will have 7 of these for a max of 72eu/tick. This is nowhere near enough for a city, but should be sufficient for my stage 1 operations until I add in methane and nuclear.