www.jamestownadvanced.com

Full disclosure...I used to own this company and my daughter does now. They will have a surface mount or pedestal box in whatever receptacle configuration you need and should be comptetive with Lowes or any other big box store. They actually make them and label them as another company's product so if you do buy at Lowes or Home Depot you may be buying their box anyway.

The electrician just needs to know how to hook up and the supply from the house needs at least a 50 amp breaker and the supply needs to be #6 wires, larger if the run is longer. A big question is if the local codes need to have a bonded neutral (the electrician should know). I prefer to keep the neutral and ground separate but it is not worth the fight with the local inspector.