So, Purr Data has a dropdown list object. and very nice too!

Here is a vanilla effort using hsliders
its colourable - good
its width can be set - good
the list will eventually cause a scrollbar if it runs off the bottom of the patch but require another event to cause it - bad good
its list is not scrollable - bad
it can only list symbols - bad
it needs all 5 arguments to instantiate - bad
and worst of all it need a local copy of the abstraction to be edited with the name of the main patch - -bad bad

I wasn't going to upload this but its quiet here, so here it is, it might be useful