hi,
I have 2 x 100W panels through a 20Amp regulator. I bought a Solar Combiner from Maplin, prod code N29KR (it will actually take 8 panels! It will have one output to your regulator. Ive used it for >2 years with 2 x 6 week trips to Europe with no issues and plenty of power from my 2 x 110ampHr batteries