Conclusion: at 2.4Ghz you get about 8-9% boost in CPU performance over 2.2Ghz. All tested Turion CPUs - ML-34, ML-37, MT-40 worked at 2.2Ghz and 2.4Ghz but stabilizing Command Rate 1T proved to be tricky. You can buy any of them, preferably ML-34 to gain the 9x CPU multiplier. You do not need to waste 200 EUR on Clawhammer 3700+.
2x Kingston HyperX 1GB memory sticks could only run CR2 at DDR400, but at decent timings 2-3-2-6.
1x Kingston HyperX 1GB + 1x OCZ Platinum 1GB could run CR1 at DDR400 at 2.4Ghz
I tried briefly also other sticks like Kingmax, Apacer but those were less stable than Kingston HyperX.
You will probably need 2xOCZ Platinum/Titanium or Corsair memory to run at CR1 or use just one stick.
Turion 64 unlocked DDR 500 support in BIOS of Gigabyte GA-K8NE, but I do not have such memory to test it. Most likely DDR-500 will be stable only with 1 memory stick.
Pentium III 900E,ECS P6BXT-A+,384MB,GeForce FX 5600, Voodoo 2,Yamaha SM718
Turion 64 MT-40@2.4Ghz,Gigabyte GA-K8NE,2GB,GeForce GTX 275,Audigy 2ZS
Phenom II X4 955,Gigabyte GA-MA770-UD3,8GB,GeForce GTX 780
Vishera FX-8370,Asus 990FX,32GB,GeForce GTX 980 Ti