My wife and I just bought our first home. We live towards the eastern end of Long Island NY and are in the process of converting to natural gas and getting our old oil tank out of the ground. We have interviewed four different plumbers so far and come up with five different ways of doing the job. We have a 1100 sq ft 3 bed 1.5 bath ranch with a full basement, well insulated attic, and may some day far down the line add another bedroom w bath on top. The house currently has an old oil fired boiler and baseboard heat and no central ac or duct work.

We have heard it all.
These are some of the options we have been given. The prices also vary wildly.

Keep the baseboards get a boiler, and indirect hot water such as a tank or a tankless. Then figure out ac later such as mini-splits or central duct work.

Get a furnace get rid of baseboards, add duct-work which you could then tie ac into and get a tankless unit for hot water.

Get rid of baseboards get a tankless unit, add a recirculating pump and run a coil through an air handler to have forced hot air and ac in one air handler.

I grew up with baseboard heat and see nothing wring with it. So at the moment I am leaning towards the first option and mini-splits for ac. We are trying to be energy efficient but not go entirely broke in the process. Any advice as to what really works would be appreciated. Thanks

Sounds like you have all the options, the next move is yours

I agree with wmproop. Now, if you are completely happy with the baseboard heat, them I say stick with it. Mini-split ac systems also work great. There are a lot of options out there, but you already have the baseboards, so a new gas boiler would make sense, as it would only require gas hook up, venting (which you may be able to use the old vent depending on the boiler you choose), and piping connection at the boiler itself.
With forced air, you would gain the option of central air conditioning, but would have the cost of tearing out baseboard, running ductwork(making access to run ductwork) etc. I say go with a new high efficient boiler, use a nondirect hot water maker that is heated by the boiler, and add mini splits when you feel financially capable of doing so.

Thanks so much. Just seems like everyone has their own opinion. This is the most expensive update we are undertaking and will stay with us forever so I want to make sure we choose wisely.

Any system you choose will work great as long as it is installed correctly. However, you say you like the hot water heat (baseboard), and I can't argue with that. It is a very efficient heat, as well as ideal for people that are prone to dust allergies, as the base boards have no forced air to stir up dust. Only downfall I can think of is you can't quickly change the temp of the home with baseboards, as they take longer to heat the space, but once you find your comfortable temp, it stays nice and steady.
The fact is, which ever way you choose will work fine as long as installed correctly as I already mentioned. Only thing is, if you go with forced air (which is what we primarily intall in our area) you will have to get used to a little extra noise and possible draft related to the, well, forced air. But trust me, if you go this route, you will get use to it in short order and probably won't even notice a difference within a couple weeks of use. Hope you are happy with whatever you decide, and please let us know how things work out.