Iím remodeling my master bathroom and am having trouble deciding on how to provide enough hot water. The bathroom specs:

- 150 gallon Jacuzzi tub.

- Custom shower with multiple body sprays and showers. If I turn everything on, shower would output 10 GPMs, although my normal operation normally would use 5-7.5 GPMs.

- I live alone so donít have to worry about other people taking showers etcÖ

Iíve had many different suggestions on how to supply hot water to this beast: two tankless heaters, large storage tank with boiler, two large hot water heaters.

I have a 405 gas meter, a ~175 BTU furnace, 75 BTU garage heater, and 75 BTU boiler heating an in-law apartment above the garage.

Iíve been doing research on the internet and think getting two 75-gal heaters with a good recovery rate (although keeping the BTUs reasonable to as not to run into a gas supply issue) is the way to go. I live up north so assume a 90 degree rise to heat the water.

This is what I came up with:

AO Smith GPS-75 Power Vent Heater. 80k BTU. 86 GPH refresh and 90 degree rise. If I did the math correctly I should be able to take a 20 min shower running 10 GPMs.

http://www.hotwater.com/lit/spec/res_gas/AOSRG45600.pdf

My questions:

- Is this a good solution or is the boiler/storage tank a better way to go? If so what would you recommend?

- Reading this forum people seem to be down on AO Smith. What tank & model do you recommended?

- Should the tanks be in series or parallel? I read something on here about potential problems if you put them in parallel but didnt understand.

I also dont understand how series would work because once you empty tank #1 wont you keep pulling cold water from that tank as it tries to refill?

- Can someone explain (or provide a link) the different venting options and the pros/cons? I donít know why one would pick one type of vent over the other.

Thanks so much for your help.