That particular K&B .35 is "Da Bomb" for NW "Super Sport" racing, if you have one (fairly rare and hard to get if you really want one), and if you can find a race to run it in. NW CL Regionals is about it for CL racing in District 11.
The K&B Universal NV Assy is #2918 from MECOA/K&B. I got some from them maybe 10 years ago, but haven't tried lately. I have 4ea in stock, $8ea. + postage if you want one/some. When I crash tested one, found that the NV didn't break...but the spraybar did. Nice unit if you like clicker-type NV's, and need a .156" dia. spraybar, which you do. Pretty cheap, too.
Most engines do use .156" spraybars, so if you need one at the field, the chances are better that somebody can fix you up, or vs. versa. OS and RO-Jetts are different, with most (but not all) OS's being smaller and RO-jetts are larger (from what I've been told). All that aside, my favorite NV Assy. is Randy Smith's...about double the dinero, but really sweet units.
Steve