Personally, I don't think right now is the time to be buying these funds.
IF (a big IF) we are in an energy bubble, you have a lot of risk. What is your estimated gains for getting in energy.
I'm not saying this is the top, but there is a reason why every energy ETF is at their 52 week high.
What is the probably of getting the first part of "buy low/sell high" correct at this time?
Just some random thoughts...
As to an actual answer to your question, I don't have any good suggestions.