Try Stratagene.It's difficult to check ur synthesis result in the process of synthesis.
Based on my experience,if ur RNA is good enough,go on ur synthesis until the step of ligation with vector,then u can check the amount of cDNA .
where do u get the idea that electroporation needs large amount of DNA?
the efficiency of heat shock is much lower than electrooration, and for such a
big plasmid, elctroportion is a practical way. Don't care about the amount of
ur DNA.Good luck.
To construct a subclone library from BAC. Perhaps u can construct a 15Kb library using phage vector.Is there any feature of ur gene for screening? If there's not,
u should disign a probe and do southen blot.Indeed I was trying to construct a 10Kb library using pUC18 as vector.Though it's not easy,but for BAC, it should be very easy since u need only a few clones.