Kevin says:

1) Is this just for plugs, or are you putting a sub panel in.
1a) If you are putting a sub panel in, what is the current.

I want to do whatever the electrical inspector is going to be more likely to sign off on. Given the layout of the room I don't think there's a good spot for the panel to go that isn't in some form of risk for water contact, so I sort of see that as being the more troublesome option. So if I went 220/240 (and I have to say, I'm really, really tempted NOT to, at this point, for reasons of both cost and effort) I think I would just go with some kind of dryer plug or oven plug (I think they're different, but I don't think it matters because you can get the ends at HD/Rona/etc. so as long as the ballasts had the right plug put on for the outlet).

Per Kevin:

If you just run some 10/3 over from your panel to your tank room, you can have 120v receptacles, and as many 220v receptacles as you want. He also says the dryer plugs are fine, or you can get 220v receptacles, and 220v cord ends, this will probably be cheaper route (the receptacles).

Kevin says he can drop by and give you a play by play, or do the work for you if you want some extra help.

The big question is how many amps you want to run;

All 240v receptacles require a 4-wire nmd cable. red (hot), black (hot), white (neutral), bare copper/green (ground).

20 amps (baseboard heaters) = 12/3
30 amps (dryer) = 10/3
40 amps (stove) = 8/3

You also have to ask the question of spending the money for a gfi circuit breaker (65 to 220 dollars depending on amperage and brand of panel).

The question you have to ask is how many watts will all the current equipment draw? Do you have 1 single 15 amp circuit for all your equipment, and your lights?

How many ballasts are you going to run in total ??

As far as savings in dollars, you won't see alot of difference.
To be honest it is not worth the expense unless you have alot of lights.
In the firm i work for we only see a 2 to 5 % difference but to places like suncor or petrocan thats alot, but to the average consumer not worth it.
Find other ways of saving money

the other issue is the timer there arent alot of options. I run a 220v aqua connect riga 2x250mh/4x54wt5 and it was a pain to wire and if you ever move you need to start all over again

I dont know alot about it but I do know more amps equals less draw which equals less heat and friction on a visit to the codfathers house i seen his set up and he had it wired to a 220v system the pump was virtually silent not so much as a hum he told me that wired to a 110v that pump was screaming so he wired it in to 220 WOW that has got to be the quietest tank ive ever heard:mrgreen my vote goes to 220v because noise is always an issue

I actually pretty much decided against 220V just looking at the cost of copper. It's cheaper to run say 5 runs using the standard household gauge (I forget what it is -14/3?) than one run of 10/3 or 12/3. I was really shocked actually at the cost of wiring and how fast it goes up from one gauge to the next. For the length of what I'd need it was the difference of several hundred dollars to have a 220V circuit or not, regardless of how many 110V's I'd put in. Crazy.

Probably a good idea. The GFI issue (how/where to get 220V GFI parts) would be the deciding factor were I ever to consider running a 220 circuit for my tank. Works well for dryers, stoves & air conditioners, but for our hobby I think it's overkill unless you've got a monster set up that needs more than a couple of kilowatts. One other thing about 220, if you ever get zapped it'll send you twice as far across the room as 110, he he. In fact it's been said that 110 is more dangerous since you may end up not being able to let go whereas 220 will definitely make you let go...

For my next tank, Im running split 120/240. So I'll have 2 circuits of 120, and a 240 source if I want to get some European stuff :D Dont cost no more, and splits the load up.