Engine repair question about 2008 Town and Country 3.8L

I am in a bit of a pickle, so I need some advice. We have a 2008 Chrysler T&C 3.8L with a little over 234k on the clock. I am pretty sure we have a bad head gasket. It leaks coolant but there are no puddles, the overflow tank bubbles when I remove the radiator cap (combustion gasses?), it blows white smoke when I start it after it’s sat overnight, and it’s throwing misfire codes. As long as I keep coolant in it, however, it doesn’t overheat and there has been no noticeable loss of power. The oil is also not milky.

My question is this: Have any of you ever used head gasket repair stuff (Bar’s, K-Seal, etc)? I know they’re a stop-gap and come with their own issues (clogged heater core, among others), but we can’t afford this repair at the moment, and it is beyond my ability.

Any thoughts, suggestions, and/or advice would be greatly appreciated.