Hi Peter,
I too bought my engine parts from Real Steel and have been very satisfied. I'm a retired engineer from the race engine business but had never built a 302 before doing one for my RCR GT40 about 18 months ago. There's plenty to read in books and on the web though! So my advice would be do your research, decide on what type of engine you want to suit your aims with the car, spec the engine in detail, check your budget and then buy the best quality parts. In my book a bog standard, driveable and reliable unit will always win over some wild thing! Power is relatively easy but associated reliability and driveability in a high performance engine is much harder to achieve.
Finally, when you come to the build, if you are not sure of something then stop and find out from experts and specialists.
You'll have a lot fun doing this engine!!!
Cheers
Roger Allen