Motherboards for 1st gen i3/i5 cpus are rather hard to come by these days.You may find such motherboards from manufacturers like mercury/zebronics etc being sold at computer stores at many places-you can check them out if you're so inclined.You're also likely to find older h55 motherboards on sites like ebay. For example,here's one that i found:
Intel H55 Chipset MotherBoard, Support 1st Generation Processor for i3,i5 and i7