Tasana Bar and Hotel was an excellent stay on Koh Lan! Even though it is very close to the port from Pattaya (don't forget the big ferry that only costs 40 baht!), the hotel sent a cart to pick us up with our luggage. The hotel is clean, spacious and luxurious with great views, water pressure and amenities. Breakfast was huge and had a good assortment of croissant, bacon, ham, sausage, fruit-topped yogurt, sliced fruit, salad, water, juice and a latte/coffee/tea.
We rented scooters from the hotel even though the rate was a bit more than if we rented them from the random people at the pier, but it was super convenient since they were parked right outside the door. The island isn't huge but there is a lot to explore with the bike, just be aware of the one-way street(s?) and the scary narrow path between Tawaen and Tien Beaches (but it was still fun).
Tasana is a definite recommendation!