If you have the budget, you could do what the previous commenter said and hire an English speaking freelancer to voiceover your videos. I believe there was a thread somewhere here a couple of weeks ago where people were discussing text to speech options so do a quick forum search and you should find that info.
There are ways to make good videos promoting products without any voice over at all that you might want to consider, you'll have to get a little creative to make an engaging video though. I have a channel running at the moment where we edit the official product trailers into a seemingly unique videos, make a top 3-5 compilation of related products, then upload the video with Amazon affiliate links in the description and bot to the top.
Good luck