There are a few hot water tank dealers. German Pool is the one that I know. They will charge nominal fee for installation. The no. is 2333-6240
or
gphkltd@netvigator.com or www.germanool.com to view the spec for the heaters.
Check on trading post as well as you might find some 2nd hand hot water heaters at dirt cheap price.
Can't help you with the contractor's name. Sorry.