I agree, find a 880 casting Vortec 350 as a start. These come with factory roller cams and Vortec heads. With the correct pieces it's easy to get this engine to produce nice power figures. However, I wouldn't waste my time on a 283. While they were excellant engines, the small journal rods these engines came with are not very strong. Especially when you consider if they are stock they are over 40 years old.
The next thing I recommend is learning more about how to hot rod a small block. When you believe things you hear such as all 327's had high compression it shows you have a lot to learn. Next thing I can tell you also is
Lets say we have a stock, 8:1 compression 350 engine. We remove the stock heads and install a set of stock 305 heads with 58cc chambers. Now the compression shot up to 10:1 thanks to the smaller chamber. However when we drive it, we notice it seems to be more throttle responsive, and seems to have better low end torque than it did, but when it reaches 4000 RPM it falls flat on it's face just like the stock heads we removed did. Why? because the small valves in the 305 heads and the stock ports aren't designed to breathe any higher. The ports on the heads we removed aren't any better even so they used a larger valve. What am I getting at here? FLOW IS POWER. Many believe high compression is the ticket to big power, and it is, as long as the flow is there to support it. Many a novice rodder you can ask this question. Which would you rather have, a high compression engine that doesn't flow very well, or a low compression engine with good flowing heads? And the majority will say the high compression with low flow. But in reality, the low compression good flowing engine will eat the other alive. A Good book to get is David Vizards hot rodding small blocks on a budget.
Don't waste your money on camel back heads. Those are now things of the past and they aren't worth investing any money into. Especially when you can get Vortec heads on the cheap and make 30 more horses with them.
If you get a set of camel backs that are stock and need a complete rebuild, your looking at around $700 as they will need valves, hardended valve seats installed, new bronze guides, skim milled to assure flatness, new springs, locks and retainers plus worked. When Vortec heads were readily avalible me and my best friend quickly sold all the camel back heads we had.
You can get a set of Vortec heads for around $600 and still be power over the camel backs. Another thing to remember is if you have poor flowing heads you can't count on the intake to improve it any so sticking a tunnel ram on a stock set of heads won't do it any good.