The rubber PCV hoses that connect from the driver’s side rear of the engine (valve cover) to the PCV valve may need replacing. The do deteriorate with age and can leak oil. Get those from the dealer only.
It looks like you have the heat exchanger (the metal canister in the middle of those hoses). You would need to buy the hose for a ‘99 intrepid with 3.2 engine. It would be one hose that you would cut in two pieces to make the connections. That will save you a good bit of money because the only PCV hoses they still carry for the 2.7 come only with the heat exchanger attaches, and they want a lot of money.
Look at the orange spots towards the front of the engine at the bottom of your photo. That is coolant (water and antifreeze) leaking from that black plastic housing with the metal bleeder at the top. That housing fails and you lose all of your coolant with the risk of damage to the engine. Oh - wait! I think that’s what you are referring to as the thermostat housing. It’s actually not.
I have some advice: If you don’t know much about working on cars, these cars at the age they now are can take a lot of time and money to keep them going. It can get really expensive if you won’t be able to do your own work. Understood if you can’t afford to get rid of this one and get something newer.
Free advice and worth every penny!
If you do hang on to it, we can advise you along the way. We can also advise you on which parts to get in aftermarket and which ones to get from the dealer. For example, the PCV valve is better to get in aftermarket in my opinion, but the black coolant housings in aftermarket are an older design and very poor quality - typically will fail in less than two years. You might want to read this very recent thread - especially post no. 5 about getting the OEM coolant housing but saving money by buying it from eBay - but eBay also sells the junk aftermarket ones - so pay attention to how to make sure you get only the OEM one, but pay a lot less than from the Chrysler dealer.
EDIT: Here's the link I left out - see post no. 5: