Appropriate oil to infuse with hot chillies
Either oil will work just fine for infusing with chillies, at the end of the day just about any cooking oil will work. Infusing oil with chilli won't change its cooking properties, and both those oils will store fine long-term. 

If you are going to go for a cold infusion then it's highly recommended that you dry your chillies first so you get a long lasting result. If you don't dry them they will get mushy and rot in the oil, which isn't very pleasant. Drying them in your oven will stink up your house big-time, but it's worth it. 

Alternatively you can make chili strings with them and they will air dry, or you can freeze them for years and they'll stay good.