Most (practically all) can be set as the specialized gizmo: for example, you use two of them to create a point-to-point wireless link. Then you can add another wireless router (using a cable) to the one at the end, to be your access point.
Some can play the role of the specialized gizmo (the bridge) and the access point.
Some can only be access points.
Basically, you halve the number of devices you need with the dual-purpose devices.
If the stuff you have is generic branded kit, you may be able to re-flash it back to UK or US English.
If some of it is Linksys, for example, and you're an adventurous person, you might be able to re-flash it using third-party software that adds features.
An example of a "do everything" device is the Linksys WET54G (which is probably discontinued) or the Linksys WAP2000 which is a "really do everything" device. But since you admirably want to re-use your existing stuff, simply use the internet to discover their complete specifications, and carry on from there.
One thing to be careful with is choosing the channels for the various devices: you have 11-14 channels available depending on your country, but you basically need to use the lowest, the highest, and the one in the middle to minimise interference.
If you think you have to spend money at any point, I'd personally go for ethernet over power, which would be the equivalent of the bridge parts of your network, and way simpler to install/understand unless you have a thing for multiple wireless devices, interference, and screwing up the DHCP.