AmSnow.com is now SnoWest.com
Conclusion
What works? All of the above.
The principles of performance tuning have not changed, even though technology has. Aftermarket suppliers today have invested millions of dollars in R&D to bring some excellent performance products to the market. Does everything work perfectly? No. But the quality products rise to the top and do work.
If you are modifying your sled, the best suggestion is to do your homework. Start with a budget and the specific results you are looking for. With a little research you can find the performance and the modifications you want!