Need more information. Size of entire home, one story or two. Well insulated or not. Does the oil furnace also heat your hot water etc.? Assume southeastern PA as location based on your profile.

The only thing I can say is that I personnaly would not purchase the Tappan or other branded units that have been recently introduced with this same technology (variable speed compressor/refrigerant flow) other than mini split models until they have been out in the field a lot longer. Very few HVAC techs have been trained on them. Their more complex. I do realize that mini splits with inverter technology(which most major brands now use) are based on the same technology. They however have been used in Japan and other countries for many years. If going with a mini split multi airhandler unit I'd suggest Mitsubishi or Daikin.

What kind of heat do you have now, forced air or hydronic?

I like my mini-splits, but I live in a very hot, humid climate and my ducts were outside of home's envelope.

Hi, i live in SE Pa., i have summer/winter hookup with oil burner, baseboard heat. The upstairs is only 2 - 150 sq. ft. rooms with very tiny hallway and tiny bathroom, it is a cape code. My family room i am putting a Fujitsu 12LRS2 in for the 550 sq. ft. area, that unit is crazy efficient at 25 seer and 12 HSPF, plus $300 rebate.
But i am considering the LG dual zone units for upstairs strictly because they are rated better at 21.7 SEER, compared to the Fujitsu 17 SEER.
I do not think i am going with the Tappan now due to our budget.

I've made a lot of comments here about mini splits. See if you can pull them up with a search. Off the top of my head:

Those rooms are awfully small to be putting a mini split in each one. Do you have heat load calculations? You might be better off with a small ducted unit stuck somewhere if you have room. Ducts are best installed in the living space. How high is the hallway ceiling; can you fur it down?

From my limited experience, the 1:1 units are more efficient than the multi splits. There another characteristic that goes unnoticed in comparing multis to 1:1 equipment. Assume that your outdoor inverter units can throttle back to 10% total capacity. Assume that you have two 6000 BTU indoor units. The outdoor unit in a 1:1 situation will be able to throttle back to 600 BTU. In a multi situation, if you are running one indoor unit and assume that the outdoor unit is rated at 20,000 BTU, the minimum will be 10% of that or 2000 BTU. In the latter situation, the indoor unit will be snapping on and off a lot more than in the former. Another thing to keep your eye on is the functionality of your remotes. My Mitsubishi remotes will not do a true set-back, only on/off. I don't do much heating so it is not as big of a deal for me as it would be in Penna. I like to sleep cool and have the room warm when I get out of bed.

In the factory programming the fan slows down as the set point is approached. In the heating mode, the high-wall-mounted units become ceiling heaters in my experience. It is kind of predictable given that the intake and supply are both up high. A higher, manually-set fan speed and a ceiling fan are both solutions this problem.

So ionized, you would go with 1 unit in my sons room to heat/cool the whole upstairs? See, that is the problem, i dont think mounting the unit in 1 of the bedrooms is pariculary good being i have 2 boys, 12 and 9, who like to close their doors on one another.
I think my only choice is to run a multi in each room. Fujitsu does make a 7K btu. I know the singles have much better efficiency ratings. I would love to get just one unit up there but i have no where to mount it.