Actually, the Schwinn Tango @ $600 (or whatever they're selling for these days) does have independent pedaling. Unfortunately, from all accounts the quality truly is spotty at best.

I also believe the Independent Pedaling System (IPS) developed by Advanced Transportation Products / Vision Recumbents years ago is still being offered and can be retrofit onto any tandem: it's basically a replacement drive-side crankset and the cost not significantly higher than a good crankset. You'll find mention of it on places like EasyStreetRecumbents.com and elsewhere by Googling.

Anyway, 99% of the folks who ride tandems do so using the traditional, linked crank systems without any problems. The IPS is a great innovation as well and most folks who use it love it, even those who didn't think they would. However, as noted, even on daVinci's newest, lower-cost models it's well beyond the price band the OP is shopping for.

My recommendation is to go with your plan on the Kent and be committed to returning it to get your money back if things don't pan out. Alternatively, you could check out garage sales & Craigslist in your local area for used Schwinn tandems from the 60's - late 70's: they're cheap but durable and will let you decide if you want to spend anymore on a tandem to meet your recreational needs.

Finally, do a search of the BikeForums.net archives for postings by BAH regarding their Extracycle tandems. You don't have to do the ExtraCycle part but they can certainly comment on the quality / performance of the Electra tandem they used for their Extracycle two-fer.