Heynanei,
I also wish you in the best when you make aliyah. Taking six years to prepare is a great idea ! As there is alot to prepare for. First of all, choosing a city is very important as it affects the quality of living. If want to be in a place where there are many jobs, Tel Aviv, Jerusalem, and Haifa are the job cities, but are also more expensive in real estate, groceries,etc. It is easier to find a job in Tel Aviv or in Haifa than in Jerusalem though. If you are looking for an "active" city Tel Aviv is very active with much to do, while most the other cities in Israel don't have so much variety. Tel Aviv is very ugly with polution and not much nature. Those who work in Tel Aviv and love nature usually go to the "Sharon" area ( Herzilliyah, Hod HaSharon, Ramat HaSharon, Cfar Saba, Rosh HaAyin, etc.). Or you could go to some of the close Yesha settlements to Tel Aviv which provide an incredible cheap housing for quality of life ( Oranit, Male Adumim, Sharey Tikvah, Ariel, etc.). OUt of all the Yesha settlements near Tel Aviv I personally like Sharey Tikvah, its on the border and is beautiful without threat of living way in the settlements and is 3 mins from shopping at Rosh HaAyin. If you like Orthodox neighborhoods near Tel Aviv B'nei Barak. If you like a secular atmosphere that is not cheap, but not expensive in Tel Aviv- Ramat Gan. Just remember that most of the Gush Dan ( Tel Aviv) area is very polluted and not much nature. I live in Tel Aviv, Bnei Barak- Ramat Gan border, because that is where the people are and Yeshua loves people.
Jerusalem is a whole nother country altogether with spiritual implifcations. I would advise you to prepare yourself with the spirit of grace to fight the spirit of legalism and relegion in Jerusalem. Someone once told me that Jerusalem has the biggest open heaven in the world as well as the most spiritual opression at the same time. Jerusalem is a very beautiful city though. It doesn't have as many jobs as Tel Aviv or Haifa.
Haifa is also a very beautiful city with lots of jobs and not much polution. Its an ultra-secular city so relegious types don't fit in much. Its the city with the most unity between Arabs and Jews in working together. It also has the Mount Carmel of Elijah, but is now filled with another Baal sign as the whole mountain is covered by the Bahai gardens ( they are beautiful, one day I hope those will be Yeshua's gardens).
The dessert ( Beer Sheva, moshavim) provides cheaper housing away from all the mess with the suicide bombings, but is far from jobs. Again lots of nature.
Ashkelon, Ashdod, Gan Yavne, Sderot, are all a one our drive from jobs in Tel Aviv with much nature near the coastline. Gaza isn't far, but there is a wall around Gaza now. They are usually nice quality housing near the coastline for very cheap prices. I especially like Gan Yavne.
Eilat, hahaha far from any Arab intrusions and mostly a vacation city. There are moshavs and kibutzes there to work on if you try to apply to be in the messech althouh kibbutzes are not thriving anymore.
The Galilee is beautiful ( Tzfat, Tiberias,Poria, Nazareth Illit, Afula, Kiryat Shmona, Mettulla, etc.) with very cheap mortgages, and even as cheap as they are now the government is helping now even more to populate the region. Of course you have the Sea of Galilee and Jordan River and it is the easiest place to pray and feel the Spirit of God without warfare in all of Israel.
The Golan Heights, where I would live if my job and the people weren't in Tel Aviv. The most beautiful place in all of Israel IMO. Katzarin is a nice city. There are also many moshavs. Mount Hermon is a beautiful background.