I would like a recommendation from the experts. I have a 10+ year old 3000 sq ft. New England house with a warm air furnace. Have seperate trunks for upstairs and downstairs, seperate oil fired HWH. Currently uses a 5 ton outdoor unit. Want to upgrade to hydro air using two air handlers and condensers, boiler with indirect HWH for domestic HW. My main question is should I pay the additional money for variable speed air handlers? I plan on using 12 seer single speed 3 ton (adding basement cooling) outdoor units due to the relativly short cooling season, but like the benefits of variable speed handlers (quiet, low speed and ramping speed heating). Two contrators are trying to talk me out of spending the money on variable speed units. The other question I have is do I need humidity control thermostats, or is there a significant benefit for those in New England?