Can someone recommend good inexpensive wireless flash triggers?

Trying to get or retain maximum sync speed (1/200th) with the 5D series cameras has always been hit and miss, even with a PC sync cord which has no delay at all. And it varies from one camera to the next.

The Strato II are pretty fast, but that 1/200th may be more than you can reasonably expect at any battery power. Looks like your Skyports are only getting 1/160th at best - http://forums.dpreview.com/forums/read.asp?forum=1025&message=42330163

But you may have a genuine issue, I couldn't say without having your gear and looking into this more deeply. But I tried to help you once before and just wasted my time so I'm not doing it again sorry. You're welcome to believe whatever you prefer.