Hi Angaria.
As I have been known to have problems with carbon resistors in certain placement´s I ll leave the advice on those to Lon or some other local expert on radials (I´m still in the process of building mine
) . But bias aside I gather Riken´s are highly regarded but I dont´think they were made in the 5w flavour. Most of my old resistors look like Allen Bradley´s or tantalum´s ( I spent a lot of time 20 years ago stripping out old gear for parts, as I had no money!) I think that in the 5w region your best bet might be Vishay resistors but to each his own and all things are relative