I want to use custom styled Map using TileMill. Found a very good style (http://a.tiles.mapbox.com/v3/aj.Sketchy2/page.html#6/34.044/10.942) in which I want to some changes, host it and use it. (Already found its style).
I've before used mapbox and Tilemill for creating mbtiles for building level, which usually creates mbtiles of less then 10 MB, later I used to upload it to Mapbox free account and use. But this Time I need to work on world level map with Few Layers like country boundaries, city boundaries with roads for few cities (OSM Data).
I've already done changes to the style using TileMill software. Now I am not sure How and where I can host these map as if I export this world map it will be a huge.
What is the most feasible way to export customized world map from TileMill and where I can host it?
Yes, exporting such a world map at a high range of zoom levels is incredibly large. Mapbox isn't really optimized for that sort of map size, which is also why our OSM-based maps aren't available for MBTiles download -- it's not the format they are designed in.
For background, the way this works is OSM is baked down to vector tiles which are consumed by front-end servers which apply styling and render them much like TileMill does out into tiles directly that are served.
One way we're tackling this problem is with TileMill 2, which is still in development. It consumes these vector tiles from the backend server directly, allowing you to style the whole world of OSM in TileMill directly without setting up up any OSM data configurations. Then, you upload the style info to Mapbox to reproduce this on our servers.
Please contact support@mapbox.com about getting setup to upload TM2 styles, since again this isn't in full release yet. You can start playing with TM2 styling right away, though.