Regarding the identification of households across time: The first thing to note is that most income variables are part of the ASEC supplement, which is an annual supplemental survey that is a part of the CPS project. Second, it is possible to link households between ASEC samples by combining HRHHID and HRHHID2. Finally note that your match rate will be under fifty-percent for any given two-year period. This is because only half of the sample is eligible to appear in both years of any two consecutive years. Also, households and persons can drop out of the survey (due to relocation, refusing to participate, etc.).
Regarding income variables: The choice really depends on what you are looking to analyze. There are several different income variables within the CPS database, each with a slightly different description. The HHINCOME variable reports the total money income during the previous calendar year of all adult household members. This amount should equal the sum of all household members’ individual incomes as recorded in the IPUMS-CPS variable INCTOT. A key characteristic of this variable is that the persons included in the household are those present in the household at the time of the survey. People who lived in the household during the previous year but were not still living there at the time of the survey are not included; household members who lived elsewhere during the previous year but had joined the household at the time of the survey are included. On the other hand the FTOTVAL variable represents the total income from all sources for each family. Here, “family” as defined by the US Census Bureau represents groups of persons related to the head of the household. Finally, ADJGINC identifies an individual’s total gross (pre-tax) income from taxable sources minus certain items, such as individual retirement plan contributions, alimony paid, medical savings accounts, and non-reimbursed employee business expenses.
I hope this helps.