What should I do about heating in my enclosure?

I'm rehoming a friends Ball Python and I got everything from her except the enclosure and heating. I got a great deal on a 90 gallon enclosure (https://www.visionproducts.us/produc...odel-400-cage/). I was wondering how I should heat? The snake has been kept with a heat mat before but would the enclosure be warm enough with just a large heat mat from petco/petsmart? Or would a radiant heat panel be a better purchase for the size of the enclosure?

Depends on a few things. The main one being the temp of the room it will be in.

A under tank heater is not going to do anything for the air temp in the cage, and should only be used with a thermostat.

The Vision cages have a screen on the back side of the top that can accommodate a heat lamp, or just a light. So you could do a lamp with a dimmer to dial it in.

Or a radiant heat panel. They seem to be hard to get at the moment though. I know Pro Products is behind. This also will require a thermostat.

I prefer the heat panels as well. And, Pro Products I think make the best. But, as mentioned above, they are behind on production and orders. They have a 3-4 week wait, from what they themselves say right now.

I needed a heat panel recently as well, and I tried for the first the Vivarium Electronics panels. If you for the panel over the bulb, you can find them at Pangea Reptiles. I got mine in 3 days. So far I'm happy with the product, but we'll see after I've used it for a longer period of time. I still recommend Pro Products if you can wait.