With the popularity of slab lumber in recent yrs the market has been taking advantage of the trend with DIYers. I got slab lumber around here like it was 2x4's.. or so it seems. Anybody with a dead tree in the back yard is having it milled into slabs and asking crazy prices....oh well,,, gonna be lots of great deals to be had in a couple years.
Unless they hear of "air dried" lumber..Yikes...
any hooooooooo... I've seen planer bits up to 3"'s in diameter..the bit itself looked kinda iffy at best. wouldn't touch it with a 6 HP router. Personally, 2"s is about the max I'd go to or be comfortable with. And the more mass the better. Infinity has a new one that fits that bill nicely at around 100.00 with a 2' cutter. Amana has a 1 1/2" carbide bit with replaceable cutters for *GULP.*.....in the 180 neighborhood. Not my neighborhood, thats for sure...*L* Whiteside has a really nice spoil board bit for around 70 bucks. (not sure if it qualifies as a cross over or not??)
Not a big fan of bowl bits only cuz by the time you take into account the radius and overlap you're probably cutting well less than 1" worth of material with a 1 1/4" bowl bit. In the end, the set up and the jig used are every bit as critical to success as the bit being used. IMHO...A 2 1/2 hp router should be plenty big enough,,, just let the router tell you how fast and how much you can get away with.
just my 2 cents worth...