It doesn’t sound like you want to be limited to an out-and-out Carp rod and want a rod that will handle both large Carp plus the smaller species.
I have a Greys multi tip rod which came with both a 2lb test curve tip section; which I sometimes use for catching Carp up to 20lb-ish (or even bigger) on less snaggy stillwater venues and also when I’m fishing in flood conditions on my rivers for Barbel; plus a 1.5lb tip section; which I use for fish like Tench, Crucians, Barbel and smaller Carp; and this rod with its two tip sections cost me around £120.
However; if you wanted to handle much smaller species using a float then you could try a ‘Commercial’ float rod which should be able to handle the much smaller species plus Carp up to around 10 to 15lb but might tend to struggle with any fish of a larger size than that.
Or you might want to have a look at a Barbel rod which usually comes with a Quiver tip section plus an Avon type tip section of either 1.5lb or 1.7lb test (or even larger) and which has a more through actioned action and will also handle fish into double figures as well as the smaller species (on its Quivertip section).
It really depends on how big your fish are going to be and types of water you will be fishing and what methods you intend to use to catch them.
Keith