Moneywell is fairly expensive $60 on the mac app store and may be similar to banktivity. The developer has a free limited trial on his site. You may be able to export your historical data for import to a new program.
I remember my mother and her cash envelopes for each regular expense to have the money on hand when needed. Simple and worked well in the days of cash and no credit.
You might consider the free Mint.com to monitor all your bank and credit card activity. It pulls all transactions in automatically, lets you correct expense categories and you can easily find how much you spend on gas, groceries, at amazon etc.
I ran parallels and vm fusion on a macbook pro years ago but it was a terrible strain on the mac. The virtual software was also very delicate and easily broken. If you can give up your xp program and try a substiture your imac will probably be functional for years longer (big savings).
Rootsmagic 7 runs on the mac in a software wrapper containing XP that avoids using parallels and works quite well. No copy of windows is needed.