I don't know why you've selected the G1 - it was one of the better supported phones. It got all the upgrades for the first year, from 1.0 to 1.6.
Pick something like LG GW620/Eve/InTouch Max/KH5200. Released in 2010, in dozens of countries, running android 1.5, it was never updated and was fully abandoned by manufacturer and carriers in under 6 months. There are hundreds of thousands of them out there on 18 or 24 month contracts which won't expire until 2012.
It is fully capable of running android 2.2, and fortunately for some, there is an open source project which provides that. But most of the people who bought it will be spending another year or so with a needlessly obsolete and insecure phone.