Extensive use of darts can be a bit rough on a rifled bore, so the barrel material needs to be as rugged as possible. Airgun darts and BBs are almost always made of mild steel so 'softer' metals will be affected more quickly and seriously by their frequent use. Even the most expensive airgun barrels are made of relatively 'soft' steel, which is why most of the makers recommend that owners stick to pellets.
IMO, it's better to pick a "BB" model gun if you're going to use darts. Most are smoothbores, but darts and BBs don't require spinning to stabilize anyway. 25 or 30 ft. is about as far as I use either. They generally aren't being pushed faster than about 400 f/s and shed velocity quickly.
It's kinda tough to find a BB gun anymore that's compatible with the use of darts. They need to have a mechanism where the breech is easy to access for loading, and that in itself eliminates about everything currently on the market. Darts aren't very compatible with any magazine arrangement I recall ever seeing, so single-loading is necessary.
I use the old Marksman because they're simple, very inexpensive, readily available, and the design makes it easy and convenient to use with darts. They're very low-powered and the barrel length is miniscule, but at 10-20 ft who cares?
It's a toy, not a tool. I use it as such and don't expect more of it than cheap fun. Darts don't really have much practical utility otherwise, if you're expecting pests much bigger than mice, IMO.
Truthfully, about any airgun with a design where the breech is exposed enough to load them could be used. A pneumatic design where you can control velocity or a low-powered springer is probably best. Daisy used to make a couple of pistol models that'd work well. They were priced a good bit above the venerable Marksman, but they were a good bit more sophisticated, too. I suppose it's pretty much a matter of how many different jobs you want it to do and how much you're willing to spend.