When it comes to home heating, forced hot water heating systems are still one of the best options on the market - amazing to thing that they were used by the romans and can still be recommended today!
In diagrammatic terms, there is not much to hydronic heating systems. You need water, which most people have on tap or from a reliable well, of course. The water must be heated by a boiler, then forced by a pump to some system of radiators around the home. That is it - three components - boiler, pump and radiators.
There are choices to be made in all these areas of course, though the pump is not usually a choice many consumers bother with - it comes as part of a central heating boiler and is well designed to do the job you specify.
In the field of boilers there are plenty of choices you must make. First what fuel source? Gas (natural, propane in liquid form), home heating oil, coal, wood, electricity...? Each has supporters and modern, fuel-efficient choices are available in each.
Even when you decide that you want, say, a gas central heating boiler, you must decide who to go with and how much to pay. If you can afford it, you should always go for the most efficient boiler. These days there are gas options that use condenser technology to be about 95% efficient.
And finally there is plenty of choice in the radiator system - wall hanging radiators, baseboard rads, hydronic radiant floor heating systems?