The A7V (KT133) supports any Athlon with a 100Mhz DDR (200Mhz effective) Front Side Bus.
The 1.0Ghz, 1.1Ghz, 1.2Ghz are all available in 100Mhz DDR FSB flavours.
There is also a 1.0Ghz, 1.13Ghz, 1.2Ghz in the 133Mhz DDR FSB flavour, for those guys you need the newer KT133A chipset (A7V133).
Anyhow, yes you can put a 1.1Ghz Athlon in an A7V. Just make sure it's an 1100/100 Athlon, not a 1133/133 version.
As for overclocking, you can go up to 12.5x (1250Mhz), just using the multiplier. You could proably tweak out a few extra with Front Side Bus increases as well.