The KJ-10H won't let you set a *specific* temperature; it does have a "keep warm" function, which essentially pulses the induction plate every 10 seconds or so. It will (roughly) attempt to retain the desired temperature range (there are 3 or 4 preset ranges). I had one for a while; the kettle itself is uncomfortable in the hand and doesn't have a great pour, so I'd try to get a different kettle to use with that base if you try to go that route. It also has an annoying "beep" that sounds for just about everything (changing modes, removing the kettle from the burner, putting it back on, etc.). You can remove it if you go inside and remove the buzzer, but that's a pain. I would not recommend this setup, especially if you already have an electric kettle.
I don't personally prefer the ones like the digital one that ITC sells, but I am pretty sure that someone else sells a similar one that's cheaper. There are also the air pot type devices, like the ones made by Zojirushi, Tiger, etc., which will let you set a temperature to maintain. Of course, they don't pour like a tea kettle.
BTW, I have seen different schools of thought about how bad keeping water at a steady boil actually is in terms of tea. I personally try to avoid it, but some folks that I trust insist it's not a big deal, and I have seen at least one fairly well regarded tea figure keep the water at a pretty steady boil. At the least, I don't think one or two quick reboils before adding fresh water should ruin the water. Some people don't like this approach (see http://teadrunk.org/viewtopic.php?id=86), but I find it works well for me. Also, most electric kettles I know of don't bring the water to that strong of a boil, nor do they maintain it once the boil is reached. So unless you're actually noticing a major difference after the kettle reboils, maybe this isn't as huge a problem as you think.
The other approach you could try is to heat the water in one place (to near a boil), then have an alcohol burner or low hot plate to keep it at a low (not rolling) boil.
Personally, I prefer to just boil the water, use it as it cools for 1-3 infusions, then top off with cool water before reboiling (with an occasional touch-up if I'm having a lazy day, though usually not to a full boil). If I'm using a tea that needs a little more heat, sometimes I'll reboil more often. I have a glass kettle, which loses heat faster than some, but if you use an earthenware kettle such as the Lin's ones, it should retain heat fairly well.