G41 chipset would be closest, as it also uses the ICH7 southbridge so your current Windows installation would boot right up on it, plus it supports up to 8GB of DDR2.
I would not recommend any Core 2 board that takes only DDR3, because of the extreme difficulty today in finding any of the extremely low-density 2Gbit DDR3 that these require, which hasn't been made in years. About the most reliable way to get them is from someone parting out a socket 1366 system and then they would come in threes, not pairs.
If you are going to change the motherboard and RAM anyway, then a new processor isn't much more. Hence the recommendation for another new computer that may provide another 10 years of service.