Engine New heat exchangers. Are some better than others?

I'm about to buy some new heat exchangers for my 1999 Mexi.


Does anyone know if there's a best buy heat exchanger?

Heritage are doing a deal for the kit at about £170. But Just Air Cooled have a much dearer kit. Are there different qualities or all crap?

I didn't fancy putting 40 year old ones on there and I know the heat won't be as good.

Any advice appreciated.