A few days ago I noticed our 40 gas hot water heater was leaking at the bottom seam (bottom of the white side). It had a number of strikes against it. About 9 to 10 years old, had been a propane heater, but later converted by a gas company contractor to natural gas (drilled jets), first seven years had well water, softened for about 4 or 5 years, TP valve hadn't been tested until now, anode never checked, last put on a water pressure meter and it immediately went to 90 pounds (leaving it on overnight to see if it goes higher).

I want to replace it with a proper natural gas model, probably a 50 gallon model. I'm looking at either Whirlpool or GE. I also want to do the install right, so planning to buy a water pressure valve and expansion tank.

Question:From what I've been reading, can I just install the valve and then the tank close to the water meter, or would there be a reason it needs to be close to the water heater? Also I've seen the larger tanks listed and also an inline model, any preferences? Any preferences to water heater brands?