Lifereef OF boxes are supposedly the best in the biz and have quite the following. I've had no experience w/ them and can't support that claim, but would encourage you to do a search on them. They claim "In the 20 years that the Lifereef Prefilter Box has been sold not one has failed to re-start when the power comes back on or has failed while in operation!" --from Lifereef.com
Personally I have used and can vouch for Eshopps overflows which, you may be interested to know, are kept in stock at at least one lfs. I must also add that I've made two important modifications to this product. 1)I bought a stockman standpipe to baffle noise and keep critters out (works famously) 2) Though I do monthly power failure tests and have never had an instance where the OF didn't restart, I continue to utilize an aqualifter pump (most of the time).