Long Shank 1/2 Rabbeting bit??

I use a tenon jig design I got from Jim McCleary (provenwoodworker) to successfully cut tenons - works perfectly. I use Whiteside rabbeting bits, with all kinds of inserts to cut off almost any amount. The tenons look like they were cut off with a laser - even on white oak or maple.

Since I only bite off 1/4" at a time, I can use my plunge router on top of the jig. My problem - I need a longer shanked router bit to cut tenons of more than 1 1/8" for heavier projects or to try some fancy arts and crafts stuff (the results merit the approach). I believe if the shank was 3.5" or more that would do the trick - they would only have to have a 1/2" cutter with at least 1/2" depth. Thus, does anyone know where I can get long shanked rabbeting router bits - the longer the better?

Thanks

An amana #45427 is 4 1/2' overall length with a 2 1/2" cutting length. Whiteside has a similar bit but I don't know the number. Both are 1/2" shank. Dick B.