Digital dispaly's are expensive but since you dont want it to be fast you cuold save some money by getting the manifold valves setup. This kit here is all 1/2'' but you can change that or slow it down. Also will have to upgrade to the digitals.
Forbidden Motorsports
I would also look into the airpod or plug and play setups. They're all enclosed and a real easy to put in. Think I saw a bunch of kits for the civic on ebay too.