I'd go bigger on the cam, it will require aftermarket springs and retainers, and different valve stem seals, but I think what you're considering is pretty small. I'd also pick a different head. I haven't priced it out, but I'm guessing you can buy a P90 or P79 and shave it and do the headwork again and still come out a hell of a lot cheaper than you can welding an N47, milling, shaping the chambers and doing the port work.
The main advantage to welding the chambers is that it increases the compression ratio. If you have the N47 on a stroker block with flat top pistons your compression is going to be really high to start with. Weld the chambers and you're talking race gas only.
There are a lot of overlapping factors here: compression ratio, camshaft, quench, octane necessary to keep the thing from pinging, timing, etc. I suggest you read some more about all of these things before you decide.