By wireless, do you mean DECT, or wireless ethernet?
The Grandstream DP715 is on Testlab; that is a SIP DECT phone with a wired connection to its base station. It can't be configured as a managed phone, but configuring it as an unmanaged station works well. Similarly there's a cordless option for the Aastra 480i which I think is the 480i CT, which is also on Testlab. While both of these are validated, keep in mind that technically speaking, anything that speaks SIP and RTP (with at least one codec in common with PureConnect) should theoretically work.
If you can still get hold of one, some Polycom Spectralink phones can be configured as managed IP phones and connect directly to wireless ethernet, rather than DECT. I believe these are now discontinued however.