Anyone has suggestions for buying a hot water urn? Is it possible to tovel a regular one or is it necessary to buy a frum one that doesn't need to be tovelled? Is there a need for Shabbos mode or any issues that need to be considered when looking into urns?

I buy regular ones and tovel the whole thing. No issues.

I’d add to just make sure to let it dry off well before plugging it in

I'll add the obligatory "ask your LOR" in terms of what you hold needs to be toiveled

How long does it need to dry after toveling? Anyone have suggestions where to get good deals?

at least 1 week keepa.com tracker on amazon

I like the pump ones because they are well insulated, making them safer, more efficient, and don't fight the AC. But the seal wears out after about 2-3 years (maybe depends on water hardness) and pumping becomes difficult. So I buy one when it goes on sale in preparation. Usually $30-40 As for toiveling, I take mine apart electrically, to the point where it's no longer functional and a maase uman to repair, and put it back together. Not for everyone (by definition, or it wouldn't help). But as @steep-dog-55906 pointed out, ask your LOR. I'm not sure what I hold, so I just do it. Takes 5 minutes, and I don't buy appliances that often (thankfully).