cant do it without all of you

So Im a building superintendent living at the building 7 yrs now Im managing. Currently renting out my two family i middlesex county If I do the conversion on my steam oil fired system I can right it off before I move back to my family home, to retire - again. My current boiler 45 yr peerless 120. Two family home built 1925 second floor flat 5 rooms bath & hall 6 radiators only one really big one Sm two family 986 sq ft , both porches 3 season. put in contractor windows in 98 . There is an old 7 inchs of fiberglass insulation in attic being gone over with 13" from home works soon. I joined this forum last week , very impressed with the knowledge of most! I look forward to your help and advice over the next week or two or 3? K majority says stay w/oil, my last oil man told me to get a new oil boiler a couple of years ago. who I lost because my tenant not wanting to sign up for the winters oil automatic fills, she is a pissa- Have new oil company but there young and dont doubt they can install a boiler but will it be tuned in??my brother in law says go gas, right it off - get rid of tank before you move back. I want what is going to heat the house best not the temp but the operation of system. I want a fine tuned boiler heating system/plant - is there such a thing with gas? My brother in law and dad installed the n 45 year old peerless 120 Ill get some pics friday and I think they did a good job? Im not good with computers so bare with me trying to download what I had for pics off phone will get boiler pics later thx for bearing w/me