I'm assuming it is a gasser, although there are a few older Bounder diesels out there. So 454 Chev or 460 Ford?
Banks are nice quality but definitely on the spendy side.
Headers make a big power difference on the older gassers. On my 460 I went with Hedman Elite coated headers and Flowmaster exhaust which all fit in the same pattern as the original and are emissions certified. Unfortunately, it appears neither are available any more for the F53 460 chassis. I did a lot of shopping for my system and the only headers I saw made specifically for the motorhome chassis were 2-into-1 so your dual exhausts wouldn't work.
Since you already have dual exhaust I must assume you are not subject to emissions testing since OEM was single exhaust on both Ford & Chev chassis. Without emissions worries you could probably run any old-school, long tube headers designed for a pickup chassis but there is always the possibility of clearance and interference problems so you are really on your own unless someone else here who has done it pipes in.
Best of luck!
1995 Coachmen Santara 360MB 36' w/slide.
Ford F53/460 chassis, 2020 Chev Equinox "toad"