Erica,
There are two C.L.s I would recomend. Both are on page 463 of the Caravan Club book.
1. R.K. Slater-Mason, Swn Y Mor, Chwilog, Pwllheli. Telephone 01766 810121. This is a level grass site. The grass is like a lawn, short and well kept.Ideal for an electric wheelchair. There are electric hook ups but you would have to use your own facilities. A lovely site.
2. Mr I.W.Ransley, Tyddyn Bach, Llanystumdwy, Criccieth. Telephone 01766 523693/512157. This is a lovely site with electric hook ups and a W.C. However the field is sloping although the pitches are almost level.
Both would be ok for an electric wheelchair but due to the fact it is completely level i would choose the first one.
Hamer