Hydraulic rollers aren't that good for high revs....and I really doubt you'll find a hydraulic roller cam suitable for spinning that high. The lifters just won't allow it. A solid roller would be my choice.
I don't see why you couldn't get 400 hp out of that little engine. You can probably go 10.5:1 with aluminum heads. I did with mine.
You can still use a carb setup....but a big cam that's suited for high rpms just won't have any low end power. Especially on a small displacement engine like a 289. No torque. No horsepower. That will make it rough on everyday driving. I guess you could supplement the high revs with a real low gear so you could get the engine up and keep it in the sweet spot as you drive.
Go to
www.compcams.com and look at their 289-302 cam catalog. Scroll down to the solid roller page and you can see what the powerbands look like. They also put little notes at the left side of the cam specs so you'll know how to prepare for it. For instance you can look at some of the high lift, high duration cams and it will tell you that you need a 3.73-4.11 gear or maybe a 3500-4000 stall converter for an automatic tranny.