I have run a couple of Windows systems on hardware, that did not support TRIM, with Intel X25-m and 320 series drives for more than a year, and the they are still alive. Windows/NTFS drive usage may not compare to Linux/EXT3, but non-TRIM usage should generally not kill the drive prematurely, only slow down writes once the amount of data matching the drive capacity has been written. Your experience with your old X25-m may have been a one-off.
I have grow a bit reluctant to recommend Sandforce-based SSDs (the 330, 335 and 520 Series) due to other reasons, but you might consider one for your use case because the internal data compression the drives utilizes, lowers the write amplification and therefore in theory should work better on systems that do not support TRIM. But other current-generation non-compressing controller designs also seem pretty robust, and a lot have happened since the X25-M hit the streets.