PCR primers design

[Nonaka Shigenori]

 Hi! We are trying to PCR-cloning by degenerate primers. What strategy
is better to design primers deduced from AA-sequence?

1.use Inosine for (A,T,C,G)mixture? or not?

2.short primers with a smaller combinations of primers or 
  longer ones with a bigger combinations?

3.addition of restriction enzyme sites to both ends of primers
  would be a drawback for the DNA amplifications?

If they have been already discussed, please inform me.

Thank you for cooperation.
---
Shigenori